CVE-2026-40324

@@ -21,8 +21,37 @@ public ParserOptions(
         NoLocations = noLocations;
         Experimental = new ParserOptionsExperimental(
             allowFragmentVariables);
+        MaxAllowedDirectives = 4;
+        MaxAllowedRecursionDepth = 200;
     }
 
+    /// <summary>
+    /// Initializes a new instance of <see cref="ParserOptions"/> with security limits.
+    /// </summary>
+    public ParserOptions(
+        bool noLocations,
+        bool allowFragmentVariables,
+        int maxAllowedDirectives,
+        int maxAllowedRecursionDepth)
+    {
+        NoLocations = noLocations;
+        Experimental = new ParserOptionsExperimental(allowFragmentVariables);
+        MaxAllowedDirectives = maxAllowedDirectives;
+        MaxAllowedRecursionDepth = maxAllowedRecursionDepth;
+    }
+
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; }
+
+    /// <summary>
+    /// Gets the maximum allowed recursion depth of a parsed document.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; }
+
     /// <summary>
     /// By default, the parser creates <see cref="ISyntaxNode" />s
     /// that know the location in the source that they correspond to.

@@ -158,5 +158,17 @@ internal static string UnexpectedToken {
                 return ResourceManager.GetString("UnexpectedToken", resourceCulture);
             }
         }
+
+        internal static string Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached", resourceCulture);
+            }
+        }
+
+        internal static string Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached", resourceCulture);
+            }
+        }
     }
 }

@@ -75,4 +75,10 @@
   <data name="UnexpectedToken" xml:space="preserve">
     <value>Unexpected token: {0}.</value>
   </data>
+  <data name="Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached" xml:space="preserve">
+    <value>A location in the GraphQL document contains more than {0} directives. Parsing aborted.</value>
+  </data>
+  <data name="Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached" xml:space="preserve">
+    <value>Document exceeds the maximum allowed recursion depth of {0}. Parsing aborted.</value>
+  </data>
 </root>

@@ -9,8 +9,11 @@ public ref partial struct Utf8GraphQLParser
 {
     private readonly bool _createLocation;
     private readonly bool _allowFragmentVars;
+    private readonly int _maxAllowedDirectives;
+    private readonly int _maxAllowedRecursionDepth;
     private Utf8GraphQLReader _reader;
     private StringValueNode? _description;
+    private int _recursionDepth;
 
     public Utf8GraphQLParser(
         ReadOnlySpan<byte> graphQLData,
@@ -24,6 +27,8 @@ public Utf8GraphQLParser(
         options ??= ParserOptions.Default;
         _createLocation = !options.NoLocations;
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = new Utf8GraphQLReader(graphQLData);
         _description = null;
     }
@@ -40,13 +45,16 @@ internal Utf8GraphQLParser(
         options ??= ParserOptions.Default;
         _createLocation = !options.NoLocations;
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = reader;
         _description = null;
     }
 
     public DocumentNode Parse()
     {
         var definitions = new List<IDefinitionNode>();
+        _recursionDepth = 0;
 
         TokenInfo start = Start();
 

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
+using static HotChocolate.Language.Properties.LangUtf8Resources;
 
 namespace HotChocolate.Language;
 
@@ -67,7 +68,7 @@ private NameNode ParseDirectiveLocation()
         throw Unexpected(kind);
     }
 
-    private List<DirectiveNode> ParseDirectives(bool isConstant)
+    private List<DirectiveNode> ParseDirectives(bool isConstant, bool isQueryLocation = false)
     {
         if (_reader.Kind == TokenKind.At)
         {
@@ -76,6 +77,15 @@ private List<DirectiveNode> ParseDirectives(bool isConstant)
             while (_reader.Kind == TokenKind.At)
             {
                 list.Add(ParseDirective(isConstant));
+
+                if (isQueryLocation && list.Count > _maxAllowedDirectives)
+                {
+                    throw new SyntaxException(
+                        _reader,
+                        string.Format(
+                            Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached,
+                            _maxAllowedDirectives));
+                }
             }
 
             return list;

@@ -58,7 +58,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
               ParseVariableDefinitions();
             ExpectOnKeyword();
             NamedTypeNode typeCondition = ParseNamedType();
-            List<DirectiveNode> directives = ParseDirectives(false);
+            List<DirectiveNode> directives = ParseDirectives(false, isQueryLocation: true);
             SelectionSetNode selectionSet = ParseSelectionSet();
             Location? location = CreateLocation(in start);
 
@@ -77,7 +77,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
             NameNode name = ParseFragmentName();
             ExpectOnKeyword();
             NamedTypeNode typeCondition = ParseNamedType();
-            List<DirectiveNode> directives = ParseDirectives(false);
+            List<DirectiveNode> directives = ParseDirectives(false, isQueryLocation: true);
             SelectionSetNode selectionSet = ParseSelectionSet();
             Location? location = CreateLocation(in start);
 
@@ -104,7 +104,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
     private FragmentSpreadNode ParseFragmentSpread(in TokenInfo start)
     {
         NameNode name = ParseFragmentName();
-        List<DirectiveNode> directives = ParseDirectives(false);
+        List<DirectiveNode> directives = ParseDirectives(false, isQueryLocation: true);
         Location? location = CreateLocation(in start);
 
         return new FragmentSpreadNode
@@ -130,7 +130,7 @@ private InlineFragmentNode ParseInlineFragment(
         in TokenInfo start,
         NamedTypeNode? typeCondition)
     {
-        List<DirectiveNode> directives = ParseDirectives(false);
+        List<DirectiveNode> directives = ParseDirectives(false, isQueryLocation: true);
         SelectionSetNode selectionSet = ParseSelectionSet();
         Location? location = CreateLocation(in start);
 

@@ -25,7 +25,7 @@ private OperationDefinitionNode ParseOperationDefinition()
         OperationType operation = ParseOperationType();
         NameNode? name = _reader.Kind == TokenKind.Name ? ParseName() : null;
         List<VariableDefinitionNode> variableDefinitions = ParseVariableDefinitions();
-        List<DirectiveNode> directives = ParseDirectives(false);
+        List<DirectiveNode> directives = ParseDirectives(false, isQueryLocation: true);
         SelectionSetNode selectionSet = ParseSelectionSet();
         Location? location = CreateLocation(in start);
 
@@ -139,7 +139,7 @@ private VariableDefinitionNode ParseVariableDefinition()
             ? ParseValueLiteral(true)
             : null;
         List<DirectiveNode> directives =
-            ParseDirectives(true);
+            ParseDirectives(true, isQueryLocation: true);
 
         Location? location = CreateLocation(in start);
 
@@ -181,6 +181,7 @@ private VariableNode ParseVariable()
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private SelectionSetNode ParseSelectionSet()
     {
+        IncreaseDepth();
         TokenInfo start = Start();
 
         if (_reader.Kind != TokenKind.LeftBrace)
@@ -208,6 +209,7 @@ private SelectionSetNode ParseSelectionSet()
 
         Location? location = CreateLocation(in start);
 
+        DecreaseDepth();
         return new SelectionSetNode
         (
             location,
@@ -253,7 +255,7 @@ private FieldNode ParseField()
 
         List<ArgumentNode> arguments = ParseArguments(false);
         INullabilityNode? required = ParseRequiredStatus();
-        List<DirectiveNode> directives = ParseDirectives(false);
+        List<DirectiveNode> directives = ParseDirectives(false, isQueryLocation: true);
         SelectionSetNode? selectionSet = _reader.Kind == TokenKind.LeftBrace
             ? ParseSelectionSet()
             : null;

@@ -12,6 +12,7 @@ public ref partial struct Utf8GraphQLParser
     /// </summary>
     private ITypeNode ParseTypeReference()
     {
+        IncreaseDepth();
         ITypeNode type;
         Location? location;
 
@@ -40,6 +41,7 @@ private ITypeNode ParseTypeReference()
                 MoveNext();
                 location = CreateLocation(in start);
 
+                DecreaseDepth();
                 return new NonNullTypeNode
                 (
                     location,
@@ -50,6 +52,7 @@ private ITypeNode ParseTypeReference()
             Unexpected(TokenKind.Bang);
         }
 
+        DecreaseDepth();
         return type;
     }
 

@@ -27,6 +27,25 @@ internal NameNode ParseName()
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal bool MoveNext() => _reader.MoveNext();
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void IncreaseDepth()
+    {
+        if (++_recursionDepth > _maxAllowedRecursionDepth)
+        {
+            throw new SyntaxException(
+                _reader,
+                string.Format(
+                    Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached,
+                    _maxAllowedRecursionDepth));
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void DecreaseDepth()
+    {
+        --_recursionDepth;
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private TokenInfo Start() =>
         _createLocation

@@ -31,32 +31,37 @@ public ref partial struct Utf8GraphQLParser
     /// </param>
     internal IValueNode ParseValueLiteral(bool isConstant)
     {
+        IncreaseDepth();
+
+        IValueNode node;
+
         if (_reader.Kind == TokenKind.LeftBracket)
         {
-            return ParseList(isConstant);
+            node = ParseList(isConstant);
         }
-
-        if (_reader.Kind == TokenKind.LeftBrace)
+        else if (_reader.Kind == TokenKind.LeftBrace)
         {
-            return ParseObject(isConstant);
+            node = ParseObject(isConstant);
         }
-
-        if (TokenHelper.IsScalarValue(in _reader))
+        else if (TokenHelper.IsScalarValue(in _reader))
         {
-            return ParseScalarValue();
+            node = ParseScalarValue();
         }
-
-        if (_reader.Kind == TokenKind.Name)
+        else if (_reader.Kind == TokenKind.Name)
         {
-            return ParseEnumValue();
+            node = ParseEnumValue();
         }
-
-        if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        else if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        {
+            node = ParseVariable();
+        }
+        else
         {
-            return ParseVariable();
+            throw Unexpected(_reader.Kind);
         }
 
-        throw Unexpected(_reader.Kind);
+        DecreaseDepth();
+        return node;
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

@@ -91,9 +91,12 @@ public static IServiceCollection AddGraphQLCore(this IServiceCollection services
 
                 return new ParserOptions(
                     noLocations: !options.IncludeLocations,
+                    allowFragmentVariables: false,
                     maxAllowedNodes: options.MaxAllowedNodes,
                     maxAllowedTokens: options.MaxAllowedTokens,
-                    maxAllowedFields: options.MaxAllowedFields);
+                    maxAllowedFields: options.MaxAllowedFields,
+                    maxAllowedDirectives: options.MaxAllowedDirectives,
+                    maxAllowedRecursionDepth: options.MaxAllowedRecursionDepth);
             });
 
         return services;

@@ -50,4 +50,17 @@ public sealed class RequestParserOptions
     /// as fields is an easier way to estimate query size for GraphQL requests.
     /// </summary>
     public int MaxAllowedFields { get; set; } = 2048;
+
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; set; } = 4;
+
+    /// <summary>
+    /// The maximum allowed recursion depth when parsing a document.
+    /// This prevents stack overflow from deeply nested queries.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; set; } = 200;
 }

@@ -42,6 +42,29 @@ public ParserOptions(
         MaxAllowedTokens = maxAllowedTokens;
         MaxAllowedNodes = maxAllowedNodes;
         MaxAllowedFields = maxAllowedFields;
+        MaxAllowedDirectives = 4;
+        MaxAllowedRecursionDepth = 200;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of <see cref="ParserOptions"/> with security limits.
+    /// </summary>
+    public ParserOptions(
+        bool noLocations,
+        bool allowFragmentVariables,
+        int maxAllowedNodes,
+        int maxAllowedTokens,
+        int maxAllowedFields,
+        int maxAllowedDirectives,
+        int maxAllowedRecursionDepth)
+    {
+        NoLocations = noLocations;
+        Experimental = new(allowFragmentVariables);
+        MaxAllowedTokens = maxAllowedTokens;
+        MaxAllowedNodes = maxAllowedNodes;
+        MaxAllowedFields = maxAllowedFields;
+        MaxAllowedDirectives = maxAllowedDirectives;
+        MaxAllowedRecursionDepth = maxAllowedRecursionDepth;
     }
 
     /// <summary>
@@ -83,6 +106,18 @@ public ParserOptions(
     /// </summary>
     public int MaxAllowedFields { get; }
 
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; }
+
+    /// <summary>
+    /// Gets the maximum allowed recursion depth of a parsed document.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; }
+
     /// <summary>
     /// Gets the experimental parser options
     /// which are by default switched of.

@@ -218,5 +218,17 @@ internal static string Utf8GraphQLParser_Start_MaxAllowedFieldsReached {
                 return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedFieldsReached", resourceCulture);
             }
         }
+
+        internal static string Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached", resourceCulture);
+            }
+        }
+
+        internal static string Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached", resourceCulture);
+            }
+        }
     }
 }

@@ -204,4 +204,10 @@
   <data name="Utf8GraphQLParser_Start_MaxAllowedFieldsReached" xml:space="preserve">
     <value>The GraphQL request document contains more than {0} fields. Parsing aborted.</value>
   </data>
+  <data name="Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached" xml:space="preserve">
+    <value>A location in the GraphQL document contains more than {0} directives. Parsing aborted.</value>
+  </data>
+  <data name="Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached" xml:space="preserve">
+    <value>Document exceeds the maximum allowed recursion depth of {0}. Parsing aborted.</value>
+  </data>
 </root>

@@ -12,10 +12,13 @@ public ref partial struct Utf8GraphQLParser
     private readonly bool _allowFragmentVars;
     private readonly int _maxAllowedNodes;
     private readonly int _maxAllowedFields;
+    private readonly int _maxAllowedDirectives;
+    private readonly int _maxAllowedRecursionDepth;
     private Utf8GraphQLReader _reader;
     private StringValueNode? _description;
     private int _parsedNodes;
     private int _parsedFields;
+    private int _recursionDepth;
 
     public Utf8GraphQLParser(
         ReadOnlySpan<byte> graphQLData,
@@ -31,6 +34,8 @@ public Utf8GraphQLParser(
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
         _maxAllowedNodes = options.MaxAllowedNodes;
         _maxAllowedFields = options.MaxAllowedFields;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = new Utf8GraphQLReader(graphQLData, options.MaxAllowedTokens);
         _description = null;
     }
@@ -49,6 +54,8 @@ internal Utf8GraphQLParser(
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
         _maxAllowedNodes = options.MaxAllowedNodes;
         _maxAllowedFields = options.MaxAllowedFields;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = reader;
         _description = null;
     }
@@ -72,6 +79,7 @@ internal Utf8GraphQLParser(
     public DocumentNode Parse()
     {
         _parsedNodes = 0;
+        _recursionDepth = 0;
         var definitions = new List<IDefinitionNode>();
 
         var start = Start();

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
+using static HotChocolate.Language.Properties.LangUtf8Resources;
 
 namespace HotChocolate.Language;
 
@@ -65,7 +66,7 @@ private NameNode ParseDirectiveLocation()
         throw Unexpected(kind);
     }
 
-    private List<DirectiveNode> ParseDirectives(bool isConstant)
+    private List<DirectiveNode> ParseDirectives(bool isConstant, bool isQueryLocation = false)
     {
         if (_reader.Kind == TokenKind.At)
         {
@@ -74,6 +75,15 @@ private List<DirectiveNode> ParseDirectives(bool isConstant)
             while (_reader.Kind == TokenKind.At)
             {
                 list.Add(ParseDirective(isConstant));
+
+                if (isQueryLocation && list.Count > _maxAllowedDirectives)
+                {
+                    throw new SyntaxException(
+                        _reader,
+                        string.Format(
+                            Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached,
+                            _maxAllowedDirectives));
+                }
             }
 
             return list;

@@ -55,7 +55,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
               ParseVariableDefinitions();
             ExpectOnKeyword();
             var typeCondition = ParseNamedType();
-            var directives = ParseDirectives(false);
+            var directives = ParseDirectives(false, isQueryLocation: true);
             var selectionSet = ParseSelectionSet();
             var location = CreateLocation(in start);
 
@@ -74,7 +74,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
             var name = ParseFragmentName();
             ExpectOnKeyword();
             var typeCondition = ParseNamedType();
-            var directives = ParseDirectives(false);
+            var directives = ParseDirectives(false, isQueryLocation: true);
             var selectionSet = ParseSelectionSet();
             var location = CreateLocation(in start);
 
@@ -101,7 +101,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
     private FragmentSpreadNode ParseFragmentSpread(in TokenInfo start)
     {
         var name = ParseFragmentName();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var location = CreateLocation(in start);
 
         return new FragmentSpreadNode
@@ -127,7 +127,7 @@ private InlineFragmentNode ParseInlineFragment(
         in TokenInfo start,
         NamedTypeNode? typeCondition)
     {
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = ParseSelectionSet();
         var location = CreateLocation(in start);
 

@@ -23,7 +23,7 @@ private OperationDefinitionNode ParseOperationDefinition()
         var operation = ParseOperationType();
         var name = _reader.Kind == TokenKind.Name ? ParseName() : null;
         var variableDefinitions = ParseVariableDefinitions();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = ParseSelectionSet();
         var location = CreateLocation(in start);
 
@@ -133,7 +133,7 @@ private VariableDefinitionNode ParseVariableDefinition()
             ? ParseValueLiteral(true)
             : null;
         var directives =
-            ParseDirectives(true);
+            ParseDirectives(isConstant: true, isQueryLocation: true);
 
         var location = CreateLocation(in start);
 
@@ -173,6 +173,7 @@ private VariableNode ParseVariable()
     /// </summary>
     private SelectionSetNode ParseSelectionSet()
     {
+        IncreaseDepth();
         var start = Start();
 
         if (_reader.Kind != TokenKind.LeftBrace)
@@ -200,6 +201,7 @@ private SelectionSetNode ParseSelectionSet()
 
         var location = CreateLocation(in start);
 
+        DecreaseDepth();
         return new SelectionSetNode
         (
             location,
@@ -252,7 +254,7 @@ private FieldNode ParseField()
 
         var arguments = ParseArguments(false);
         var required = ParseRequiredStatus();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = _reader.Kind == TokenKind.LeftBrace
             ? ParseSelectionSet()
             : null;

@@ -12,6 +12,7 @@ public ref partial struct Utf8GraphQLParser
     /// </summary>
     private ITypeNode ParseTypeReference()
     {
+        IncreaseDepth();
         ITypeNode type;
         Location? location;
 
@@ -40,6 +41,7 @@ private ITypeNode ParseTypeReference()
                 MoveNext();
                 location = CreateLocation(in start);
 
+                DecreaseDepth();
                 return new NonNullTypeNode
                 (
                     location,
@@ -50,6 +52,7 @@ private ITypeNode ParseTypeReference()
             Unexpected(TokenKind.Bang);
         }
 
+        DecreaseDepth();
         return type;
     }
 

@@ -27,6 +27,25 @@ internal NameNode ParseName()
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal bool MoveNext() => _reader.MoveNext();
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void IncreaseDepth()
+    {
+        if (++_recursionDepth > _maxAllowedRecursionDepth)
+        {
+            throw new SyntaxException(
+                _reader,
+                string.Format(
+                    Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached,
+                    _maxAllowedRecursionDepth));
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void DecreaseDepth()
+    {
+        --_recursionDepth;
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private TokenInfo Start()
     {

@@ -32,32 +32,37 @@ public ref partial struct Utf8GraphQLParser
     /// </param>
     internal IValueNode ParseValueLiteral(bool isConstant)
     {
+        IncreaseDepth();
+
+        IValueNode node;
+
         if (_reader.Kind == TokenKind.LeftBracket)
         {
-            return ParseList(isConstant);
+            node = ParseList(isConstant);
         }
-
-        if (_reader.Kind == TokenKind.LeftBrace)
+        else if (_reader.Kind == TokenKind.LeftBrace)
         {
-            return ParseObject(isConstant);
+            node = ParseObject(isConstant);
         }
-
-        if (TokenHelper.IsScalarValue(in _reader))
+        else if (TokenHelper.IsScalarValue(in _reader))
         {
-            return ParseScalarValue();
+            node = ParseScalarValue();
         }
-
-        if (_reader.Kind == TokenKind.Name)
+        else if (_reader.Kind == TokenKind.Name)
         {
-            return ParseEnumValue();
+            node = ParseEnumValue();
         }
-
-        if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        else if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        {
+            node = ParseVariable();
+        }
+        else
         {
-            return ParseVariable();
+            throw Unexpected(_reader.Kind);
         }
 
-        throw Unexpected(_reader.Kind);
+        DecreaseDepth();
+        return node;
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <RootNamespace></RootNamespace>
     <NoWarn>CS0649;CS0169</NoWarn>
     <NukeRootDirectory>..</NukeRootDirectory>

@@ -96,9 +96,12 @@ public static IServiceCollection AddGraphQLCore(this IServiceCollection services
 
                 return new ParserOptions(
                     noLocations: !options.IncludeLocations,
+                    allowFragmentVariables: false,
                     maxAllowedNodes: options.MaxAllowedNodes,
                     maxAllowedTokens: options.MaxAllowedTokens,
-                    maxAllowedFields: options.MaxAllowedFields);
+                    maxAllowedFields: options.MaxAllowedFields,
+                    maxAllowedDirectives: options.MaxAllowedDirectives,
+                    maxAllowedRecursionDepth: options.MaxAllowedRecursionDepth);
             });
 
         return services;

@@ -50,4 +50,17 @@ public sealed class RequestParserOptions
     /// as fields is an easier way to estimate query size for GraphQL requests.
     /// </summary>
     public int MaxAllowedFields { get; set; } = 2048;
+
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; set; } = 4;
+
+    /// <summary>
+    /// The maximum allowed recursion depth when parsing a document.
+    /// This prevents stack overflow from deeply nested queries.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; set; } = 200;
 }

@@ -45,6 +45,50 @@ public ParserOptions(
         MaxAllowedTokens = maxAllowedTokens;
         MaxAllowedNodes = maxAllowedNodes;
         MaxAllowedFields = maxAllowedFields;
+        MaxAllowedDirectives = 4;
+        MaxAllowedRecursionDepth = 200;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of <see cref="ParserOptions"/>.
+    /// </summary>
+    /// <param name="noLocations">
+    /// Defines that the parse shall not preserve syntax node locations.
+    /// </param>
+    /// <param name="allowFragmentVariables">
+    /// Defines that the parser shall parse fragment variables.
+    /// </param>
+    /// <param name="maxAllowedNodes">
+    /// The maximum number of nodes allowed within a document.
+    /// </param>
+    /// <param name="maxAllowedTokens">
+    /// The maximum number of tokens allowed within a document.
+    /// </param>
+    /// <param name="maxAllowedFields">
+    /// The maximum number of fields allowed within a query document.
+    /// </param>
+    /// <param name="maxAllowedDirectives">
+    /// The maximum number of directives allowed per location.
+    /// </param>
+    /// <param name="maxAllowedRecursionDepth">
+    /// The maximum allowed recursion depth of a parsed document.
+    /// </param>
+    public ParserOptions(
+        bool noLocations,
+        bool allowFragmentVariables,
+        int maxAllowedNodes,
+        int maxAllowedTokens,
+        int maxAllowedFields,
+        int maxAllowedDirectives,
+        int maxAllowedRecursionDepth)
+    {
+        NoLocations = noLocations;
+        Experimental = new(allowFragmentVariables);
+        MaxAllowedTokens = maxAllowedTokens;
+        MaxAllowedNodes = maxAllowedNodes;
+        MaxAllowedFields = maxAllowedFields;
+        MaxAllowedDirectives = maxAllowedDirectives;
+        MaxAllowedRecursionDepth = maxAllowedRecursionDepth;
     }
 
     /// <summary>
@@ -86,6 +130,18 @@ public ParserOptions(
     /// </summary>
     public int MaxAllowedFields { get; }
 
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; }
+
+    /// <summary>
+    /// Gets the maximum allowed recursion depth of a parsed document.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; }
+
     /// <summary>
     /// Gets the experimental parser options
     /// which are by default switched of.

@@ -224,5 +224,17 @@ internal static string Utf8GraphQLParser_Start_MaxAllowedFieldsReached {
                 return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedFieldsReached", resourceCulture);
             }
         }
+
+        internal static string Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached", resourceCulture);
+            }
+        }
+
+        internal static string Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached", resourceCulture);
+            }
+        }
     }
 }

@@ -207,4 +207,10 @@
   <data name="Utf8GraphQLParser_Start_MaxAllowedFieldsReached" xml:space="preserve">
     <value>The GraphQL request document contains more than {0} fields. Parsing aborted.</value>
   </data>
+  <data name="Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached" xml:space="preserve">
+    <value>A location in the GraphQL document contains more than {0} directives. Parsing aborted.</value>
+  </data>
+  <data name="Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached" xml:space="preserve">
+    <value>Document exceeds the maximum allowed recursion depth of {0}. Parsing aborted.</value>
+  </data>
 </root>

@@ -10,10 +10,13 @@ public ref partial struct Utf8GraphQLParser
     private readonly bool _allowFragmentVars;
     private readonly int _maxAllowedNodes;
     private readonly int _maxAllowedFields;
+    private readonly int _maxAllowedDirectives;
+    private readonly int _maxAllowedRecursionDepth;
     private Utf8GraphQLReader _reader;
     private StringValueNode? _description;
     private int _parsedNodes;
     private int _parsedFields;
+    private int _recursionDepth;
 
     public Utf8GraphQLParser(
         ReadOnlySpan<byte> graphQLData,
@@ -29,6 +32,8 @@ public Utf8GraphQLParser(
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
         _maxAllowedNodes = options.MaxAllowedNodes;
         _maxAllowedFields = options.MaxAllowedFields;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = new Utf8GraphQLReader(graphQLData, options.MaxAllowedTokens);
         _description = null;
     }
@@ -47,6 +52,8 @@ internal Utf8GraphQLParser(
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
         _maxAllowedNodes = options.MaxAllowedNodes;
         _maxAllowedFields = options.MaxAllowedFields;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = reader;
         _description = null;
     }
@@ -64,6 +71,7 @@ internal Utf8GraphQLParser(
     public DocumentNode Parse()
     {
         _parsedNodes = 0;
+        _recursionDepth = 0;
         var definitions = new List<IDefinitionNode>();
 
         var start = Start();

@@ -1,4 +1,5 @@
 using System.Runtime.CompilerServices;
+using static HotChocolate.Language.Properties.LangUtf8Resources;
 
 namespace HotChocolate.Language;
 
@@ -64,7 +65,7 @@ private NameNode ParseDirectiveLocation()
         throw Unexpected(kind);
     }
 
-    private List<DirectiveNode> ParseDirectives(bool isConstant)
+    private List<DirectiveNode> ParseDirectives(bool isConstant, bool isQueryLocation = false)
     {
         if (_reader.Kind == TokenKind.At)
         {
@@ -73,6 +74,15 @@ private List<DirectiveNode> ParseDirectives(bool isConstant)
             while (_reader.Kind == TokenKind.At)
             {
                 list.Add(ParseDirective(isConstant));
+
+                if (isQueryLocation && list.Count > _maxAllowedDirectives)
+                {
+                    throw new SyntaxException(
+                        _reader,
+                        string.Format(
+                            Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached,
+                            _maxAllowedDirectives));
+                }
             }
 
             return list;

@@ -53,7 +53,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
               ParseVariableDefinitions();
             ExpectOnKeyword();
             var typeCondition = ParseNamedType();
-            var directives = ParseDirectives(false);
+            var directives = ParseDirectives(false, isQueryLocation: true);
             var selectionSet = ParseSelectionSet();
             var location = CreateLocation(in start);
 
@@ -72,7 +72,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
             var name = ParseFragmentName();
             ExpectOnKeyword();
             var typeCondition = ParseNamedType();
-            var directives = ParseDirectives(false);
+            var directives = ParseDirectives(false, isQueryLocation: true);
             var selectionSet = ParseSelectionSet();
             var location = CreateLocation(in start);
 
@@ -99,7 +99,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
     private FragmentSpreadNode ParseFragmentSpread(in TokenInfo start)
     {
         var name = ParseFragmentName();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var location = CreateLocation(in start);
 
         return new FragmentSpreadNode
@@ -125,7 +125,7 @@ private InlineFragmentNode ParseInlineFragment(
         in TokenInfo start,
         NamedTypeNode? typeCondition)
     {
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = ParseSelectionSet();
         var location = CreateLocation(in start);
 

@@ -21,7 +21,7 @@ private OperationDefinitionNode ParseOperationDefinition()
         var operation = ParseOperationType();
         var name = _reader.Kind == TokenKind.Name ? ParseName() : null;
         var variableDefinitions = ParseVariableDefinitions();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = ParseSelectionSet();
         var location = CreateLocation(in start);
 
@@ -127,7 +127,7 @@ private VariableDefinitionNode ParseVariableDefinition()
             ? ParseValueLiteral(true)
             : null;
         var directives =
-            ParseDirectives(isConstant: true);
+            ParseDirectives(isConstant: true, isQueryLocation: true);
 
         var location = CreateLocation(in start);
 
@@ -163,6 +163,7 @@ private VariableNode ParseVariable()
     /// </summary>
     private SelectionSetNode ParseSelectionSet()
     {
+        IncreaseDepth();
         var start = Start();
 
         if (_reader.Kind != TokenKind.LeftBrace)
@@ -191,6 +192,7 @@ private SelectionSetNode ParseSelectionSet()
 
         var location = CreateLocation(in start);
 
+        DecreaseDepth();
         return new SelectionSetNode(
             location,
             selections);
@@ -240,7 +242,7 @@ private FieldNode ParseField()
         }
 
         var arguments = ParseArguments(false);
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = _reader.Kind == TokenKind.LeftBrace
             ? ParseSelectionSet()
             : null;

@@ -12,6 +12,7 @@ public ref partial struct Utf8GraphQLParser
     /// </summary>
     private ITypeNode ParseTypeReference()
     {
+        IncreaseDepth();
         ITypeNode type;
         Location? location;
 
@@ -40,6 +41,7 @@ private ITypeNode ParseTypeReference()
                 MoveNext();
                 location = CreateLocation(in start);
 
+                DecreaseDepth();
                 return new NonNullTypeNode
                 (
                     location,
@@ -50,6 +52,7 @@ private ITypeNode ParseTypeReference()
             Unexpected(TokenKind.Bang);
         }
 
+        DecreaseDepth();
         return type;
     }
 

@@ -24,6 +24,25 @@ private NameNode ParseName()
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private bool MoveNext() => _reader.MoveNext();
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void IncreaseDepth()
+    {
+        if (++_recursionDepth > _maxAllowedRecursionDepth)
+        {
+            throw new SyntaxException(
+                _reader,
+                string.Format(
+                    Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached,
+                    _maxAllowedRecursionDepth));
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void DecreaseDepth()
+    {
+        --_recursionDepth;
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private TokenInfo Start()
     {

@@ -29,32 +29,37 @@ public ref partial struct Utf8GraphQLParser
     /// </param>
     private IValueNode ParseValueLiteral(bool isConstant)
     {
+        IncreaseDepth();
+
+        IValueNode node;
+
         if (_reader.Kind == TokenKind.LeftBracket)
         {
-            return ParseList(isConstant);
+            node = ParseList(isConstant);
         }
-
-        if (_reader.Kind == TokenKind.LeftBrace)
+        else if (_reader.Kind == TokenKind.LeftBrace)
         {
-            return ParseObject(isConstant);
+            node = ParseObject(isConstant);
         }
-
-        if (TokenHelper.IsScalarValue(ref _reader))
+        else if (TokenHelper.IsScalarValue(ref _reader))
         {
-            return ParseScalarValue();
+            node = ParseScalarValue();
         }
-
-        if (_reader.Kind == TokenKind.Name)
+        else if (_reader.Kind == TokenKind.Name)
         {
-            return ParseEnumValue();
+            node = ParseEnumValue();
         }
-
-        if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        else if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        {
+            node = ParseVariable();
+        }
+        else
         {
-            return ParseVariable();
+            throw Unexpected(_reader.Kind);
         }
 
-        throw Unexpected(_reader.Kind);
+        DecreaseDepth();
+        return node;
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

@@ -2,6 +2,7 @@
   <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)..\'))" />
 
   <PropertyGroup>
+    <TargetFrameworks>$(TestTargetFrameworks)</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <GenerateDocumentationFile>false</GenerateDocumentationFile>
   </PropertyGroup>

@@ -94,9 +94,12 @@ public static IServiceCollection AddGraphQLCore(this IServiceCollection services
 
                 return new ParserOptions(
                     noLocations: !options.IncludeLocations,
+                    allowFragmentVariables: false,
                     maxAllowedNodes: options.MaxAllowedNodes,
                     maxAllowedTokens: options.MaxAllowedTokens,
-                    maxAllowedFields: options.MaxAllowedFields);
+                    maxAllowedFields: options.MaxAllowedFields,
+                    maxAllowedDirectives: options.MaxAllowedDirectives,
+                    maxAllowedRecursionDepth: options.MaxAllowedRecursionDepth);
             });
 
         return services;

@@ -50,4 +50,17 @@ public sealed class RequestParserOptions
     /// as fields is an easier way to estimate query size for GraphQL requests.
     /// </summary>
     public int MaxAllowedFields { get; set; } = 2048;
+
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; set; } = 4;
+
+    /// <summary>
+    /// The maximum allowed recursion depth when parsing a document.
+    /// This prevents stack overflow from deeply nested queries.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; set; } = 200;
 }

@@ -45,6 +45,51 @@ public ParserOptions(
         MaxAllowedTokens = maxAllowedTokens;
         MaxAllowedNodes = maxAllowedNodes;
         MaxAllowedFields = maxAllowedFields;
+        MaxAllowedDirectives = 4;
+        MaxAllowedRecursionDepth = 200;
+    }
+
+    /// <summary>
+    /// Initializes a new instance of <see cref="ParserOptions"/> with security limits.
+    /// </summary>
+    /// <param name="noLocations">
+    /// Defines that the parse shall not preserve syntax node locations.
+    /// </param>
+    /// <param name="allowFragmentVariables">
+    /// Defines that the parser shall parse fragment variables.
+    /// </param>
+    /// <param name="maxAllowedNodes">
+    /// The maximum number of nodes allowed within a document.
+    /// </param>
+    /// <param name="maxAllowedTokens">
+    /// The maximum number of tokens allowed within a document.
+    /// </param>
+    /// <param name="maxAllowedFields">
+    /// The maximum number of fields allowed within a query document.
+    /// </param>
+    /// <param name="maxAllowedDirectives">
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition).
+    /// </param>
+    /// <param name="maxAllowedRecursionDepth">
+    /// The maximum allowed recursion depth of a parsed document.
+    /// </param>
+    public ParserOptions(
+        bool noLocations,
+        bool allowFragmentVariables,
+        int maxAllowedNodes,
+        int maxAllowedTokens,
+        int maxAllowedFields,
+        int maxAllowedDirectives,
+        int maxAllowedRecursionDepth)
+    {
+        NoLocations = noLocations;
+        Experimental = new(allowFragmentVariables);
+        MaxAllowedTokens = maxAllowedTokens;
+        MaxAllowedNodes = maxAllowedNodes;
+        MaxAllowedFields = maxAllowedFields;
+        MaxAllowedDirectives = maxAllowedDirectives;
+        MaxAllowedRecursionDepth = maxAllowedRecursionDepth;
     }
 
     /// <summary>
@@ -86,6 +131,18 @@ public ParserOptions(
     /// </summary>
     public int MaxAllowedFields { get; }
 
+    /// <summary>
+    /// The maximum number of directives allowed per location (e.g. per field,
+    /// per operation, per fragment definition). Repeatable directives can be used
+    /// to exhaust CPU and memory resources if not limited.
+    /// </summary>
+    public int MaxAllowedDirectives { get; }
+
+    /// <summary>
+    /// Gets the maximum allowed recursion depth of a parsed document.
+    /// </summary>
+    public int MaxAllowedRecursionDepth { get; }
+
     /// <summary>
     /// Gets the experimental parser options
     /// which are by default switched of.

@@ -224,5 +224,17 @@ internal static string Utf8GraphQLParser_Start_MaxAllowedFieldsReached {
                 return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedFieldsReached", resourceCulture);
             }
         }
+
+        internal static string Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached", resourceCulture);
+            }
+        }
+
+        internal static string Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached {
+            get {
+                return ResourceManager.GetString("Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached", resourceCulture);
+            }
+        }
     }
 }

@@ -207,4 +207,10 @@
   <data name="Utf8GraphQLParser_Start_MaxAllowedFieldsReached" xml:space="preserve">
     <value>The GraphQL request document contains more than {0} fields. Parsing aborted.</value>
   </data>
+  <data name="Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached" xml:space="preserve">
+    <value>A location in the GraphQL document contains more than {0} directives. Parsing aborted.</value>
+  </data>
+  <data name="Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached" xml:space="preserve">
+    <value>Document exceeds the maximum allowed recursion depth of {0}. Parsing aborted.</value>
+  </data>
 </root>

@@ -10,10 +10,13 @@ public ref partial struct Utf8GraphQLParser
     private readonly bool _allowFragmentVars;
     private readonly int _maxAllowedNodes;
     private readonly int _maxAllowedFields;
+    private readonly int _maxAllowedDirectives;
+    private readonly int _maxAllowedRecursionDepth;
     private Utf8GraphQLReader _reader;
     private StringValueNode? _description;
     private int _parsedNodes;
     private int _parsedFields;
+    private int _recursionDepth;
 
     public Utf8GraphQLParser(
         ReadOnlySpan<byte> graphQLData,
@@ -29,6 +32,8 @@ public Utf8GraphQLParser(
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
         _maxAllowedNodes = options.MaxAllowedNodes;
         _maxAllowedFields = options.MaxAllowedFields;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = new Utf8GraphQLReader(graphQLData, options.MaxAllowedTokens);
         _description = null;
     }
@@ -47,6 +52,8 @@ internal Utf8GraphQLParser(
         _allowFragmentVars = options.Experimental.AllowFragmentVariables;
         _maxAllowedNodes = options.MaxAllowedNodes;
         _maxAllowedFields = options.MaxAllowedFields;
+        _maxAllowedDirectives = options.MaxAllowedDirectives;
+        _maxAllowedRecursionDepth = options.MaxAllowedRecursionDepth;
         _reader = reader;
         _description = null;
     }
@@ -64,6 +71,7 @@ internal Utf8GraphQLParser(
     public DocumentNode Parse()
     {
         _parsedNodes = 0;
+        _recursionDepth = 0;
         var definitions = new List<IDefinitionNode>();
 
         var start = Start();

@@ -1,4 +1,5 @@
 using System.Runtime.CompilerServices;
+using static HotChocolate.Language.Properties.LangUtf8Resources;
 
 namespace HotChocolate.Language;
 
@@ -64,7 +65,7 @@ private NameNode ParseDirectiveLocation()
         throw Unexpected(kind);
     }
 
-    private List<DirectiveNode> ParseDirectives(bool isConstant)
+    private List<DirectiveNode> ParseDirectives(bool isConstant, bool isQueryLocation = false)
     {
         if (_reader.Kind == TokenKind.At)
         {
@@ -73,6 +74,15 @@ private List<DirectiveNode> ParseDirectives(bool isConstant)
             while (_reader.Kind == TokenKind.At)
             {
                 list.Add(ParseDirective(isConstant));
+
+                if (isQueryLocation && list.Count > _maxAllowedDirectives)
+                {
+                    throw new SyntaxException(
+                        _reader,
+                        string.Format(
+                            Utf8GraphQLParser_ParseDirective_MaxAllowedDirectivesReached,
+                            _maxAllowedDirectives));
+                }
             }
 
             return list;

@@ -53,7 +53,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
               ParseVariableDefinitions();
             ExpectOnKeyword();
             var typeCondition = ParseNamedType();
-            var directives = ParseDirectives(false);
+            var directives = ParseDirectives(false, isQueryLocation: true);
             var selectionSet = ParseSelectionSet();
             var location = CreateLocation(in start);
 
@@ -72,7 +72,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
             var name = ParseFragmentName();
             ExpectOnKeyword();
             var typeCondition = ParseNamedType();
-            var directives = ParseDirectives(false);
+            var directives = ParseDirectives(false, isQueryLocation: true);
             var selectionSet = ParseSelectionSet();
             var location = CreateLocation(in start);
 
@@ -99,7 +99,7 @@ private FragmentDefinitionNode ParseFragmentDefinition()
     private FragmentSpreadNode ParseFragmentSpread(in TokenInfo start)
     {
         var name = ParseFragmentName();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var location = CreateLocation(in start);
 
         return new FragmentSpreadNode
@@ -125,7 +125,7 @@ private InlineFragmentNode ParseInlineFragment(
         in TokenInfo start,
         NamedTypeNode? typeCondition)
     {
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = ParseSelectionSet();
         var location = CreateLocation(in start);
 

@@ -21,7 +21,7 @@ private OperationDefinitionNode ParseOperationDefinition()
         var operation = ParseOperationType();
         var name = _reader.Kind == TokenKind.Name ? ParseName() : null;
         var variableDefinitions = ParseVariableDefinitions();
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = ParseSelectionSet();
         var location = CreateLocation(in start);
 
@@ -127,7 +127,7 @@ private VariableDefinitionNode ParseVariableDefinition()
             ? ParseValueLiteral(true)
             : null;
         var directives =
-            ParseDirectives(isConstant: true);
+            ParseDirectives(isConstant: true, isQueryLocation: true);
 
         var location = CreateLocation(in start);
 
@@ -163,6 +163,7 @@ private VariableNode ParseVariable()
     /// </summary>
     private SelectionSetNode ParseSelectionSet()
     {
+        IncreaseDepth();
         var start = Start();
 
         if (_reader.Kind != TokenKind.LeftBrace)
@@ -191,6 +192,7 @@ private SelectionSetNode ParseSelectionSet()
 
         var location = CreateLocation(in start);
 
+        DecreaseDepth();
         return new SelectionSetNode(
             location,
             selections);
@@ -240,7 +242,7 @@ private FieldNode ParseField()
         }
 
         var arguments = ParseArguments(false);
-        var directives = ParseDirectives(false);
+        var directives = ParseDirectives(false, isQueryLocation: true);
         var selectionSet = _reader.Kind == TokenKind.LeftBrace
             ? ParseSelectionSet()
             : null;

@@ -12,6 +12,7 @@ public ref partial struct Utf8GraphQLParser
     /// </summary>
     private ITypeNode ParseTypeReference()
     {
+        IncreaseDepth();
         ITypeNode type;
         Location? location;
 
@@ -40,6 +41,7 @@ private ITypeNode ParseTypeReference()
                 MoveNext();
                 location = CreateLocation(in start);
 
+                DecreaseDepth();
                 return new NonNullTypeNode
                 (
                     location,
@@ -50,6 +52,7 @@ private ITypeNode ParseTypeReference()
             Unexpected(TokenKind.Bang);
         }
 
+        DecreaseDepth();
         return type;
     }
 

@@ -24,6 +24,25 @@ private NameNode ParseName()
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private bool MoveNext() => _reader.MoveNext();
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void IncreaseDepth()
+    {
+        if (++_recursionDepth > _maxAllowedRecursionDepth)
+        {
+            throw new SyntaxException(
+                _reader,
+                string.Format(
+                    Utf8GraphQLParser_Start_MaxAllowedRecursionDepthReached,
+                    _maxAllowedRecursionDepth));
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void DecreaseDepth()
+    {
+        --_recursionDepth;
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private TokenInfo Start()
     {

@@ -29,32 +29,37 @@ public ref partial struct Utf8GraphQLParser
     /// </param>
     private IValueNode ParseValueLiteral(bool isConstant)
     {
+        IncreaseDepth();
+
+        IValueNode node;
+
         if (_reader.Kind == TokenKind.LeftBracket)
         {
-            return ParseList(isConstant);
+            node = ParseList(isConstant);
         }
-
-        if (_reader.Kind == TokenKind.LeftBrace)
+        else if (_reader.Kind == TokenKind.LeftBrace)
         {
-            return ParseObject(isConstant);
+            node = ParseObject(isConstant);
         }
-
-        if (TokenHelper.IsScalarValue(ref _reader))
+        else if (TokenHelper.IsScalarValue(ref _reader))
         {
-            return ParseScalarValue();
+            node = ParseScalarValue();
         }
-
-        if (_reader.Kind == TokenKind.Name)
+        else if (_reader.Kind == TokenKind.Name)
         {
-            return ParseEnumValue();
+            node = ParseEnumValue();
         }
-
-        if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        else if (_reader.Kind == TokenKind.Dollar && !isConstant)
+        {
+            node = ParseVariable();
+        }
+        else
         {
-            return ParseVariable();
+            throw Unexpected(_reader.Kind);
         }
 
-        throw Unexpected(_reader.Kind);
+        DecreaseDepth();
+        return node;
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

@@ -6,6 +6,209 @@ namespace HotChocolate.Language;
 
 public class QueryParserTests
 {
+    [Fact]
+    public void Default_MaxAllowedRecursionDepth_Is_200()
+    {
+        Assert.Equal(200, ParserOptions.Default.MaxAllowedRecursionDepth);
+    }
+
+    [Fact]
+    public void Reject_Queries_Exceeding_Max_Recursion_Depth_Selection_Sets()
+    {
+        const int depth = 201;
+        var query = string.Concat(Enumerable.Repeat("{ a", depth))
+            + string.Concat(Enumerable.Repeat(" }", depth));
+
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query))
+            .Message
+            .MatchInlineSnapshot(
+                "Document exceeds the maximum allowed recursion depth of 200. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Reject_Queries_Exceeding_Max_Recursion_Depth_Object_Values()
+    {
+        const int depth = 201;
+        var query = "{ a(x: "
+            + string.Concat(Enumerable.Repeat("{a: ", depth))
+            + "1"
+            + string.Concat(Enumerable.Repeat("}", depth))
+            + ") }";
+
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query))
+            .Message
+            .MatchInlineSnapshot(
+                "Document exceeds the maximum allowed recursion depth of 200. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Reject_Queries_Exceeding_Max_Recursion_Depth_List_Values()
+    {
+        const int depth = 201;
+        var query = "{ a(x: "
+            + string.Concat(Enumerable.Repeat("[", depth))
+            + "1"
+            + string.Concat(Enumerable.Repeat("]", depth))
+            + ") }";
+
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query))
+            .Message
+            .MatchInlineSnapshot(
+                "Document exceeds the maximum allowed recursion depth of 200. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Reject_Queries_Exceeding_Max_Recursion_Depth_List_Types()
+    {
+        const int depth = 201;
+        var query = $"query($v: {string.Concat(Enumerable.Repeat("[", depth))}Int{string.Concat(Enumerable.Repeat("]", depth))}) {{ a }}";
+
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query))
+            .Message
+            .MatchInlineSnapshot(
+                "Document exceeds the maximum allowed recursion depth of 200. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Allow_Queries_Within_Max_Recursion_Depth()
+    {
+        const int depth = 50;
+        var query = string.Concat(Enumerable.Repeat("{ a", depth))
+            + string.Concat(Enumerable.Repeat(" }", depth));
+
+        var document = Utf8GraphQLParser.Parse(query);
+
+        Assert.NotNull(document);
+        Assert.Single(document.Definitions);
+    }
+
+    [Fact]
+    public void Reject_Queries_Exceeding_Custom_Recursion_Depth()
+    {
+        var options = new ParserOptions(
+            noLocations: false,
+            allowFragmentVariables: false,
+            maxAllowedNodes: int.MaxValue,
+            maxAllowedTokens: int.MaxValue,
+            maxAllowedFields: 2048,
+            maxAllowedDirectives: 4,
+            maxAllowedRecursionDepth: 10);
+        const int depth = 11;
+        var query = string.Concat(Enumerable.Repeat("{ a", depth))
+            + string.Concat(Enumerable.Repeat(" }", depth));
+
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query, options))
+            .Message
+            .MatchInlineSnapshot(
+                "Document exceeds the maximum allowed recursion depth of 10. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Allow_Queries_Within_Custom_Recursion_Depth()
+    {
+        var options = new ParserOptions(
+            noLocations: false,
+            allowFragmentVariables: false,
+            maxAllowedNodes: int.MaxValue,
+            maxAllowedTokens: int.MaxValue,
+            maxAllowedFields: 2048,
+            maxAllowedDirectives: 4,
+            maxAllowedRecursionDepth: 10);
+        const int depth = 10;
+        var query = string.Concat(Enumerable.Repeat("{ a", depth))
+            + string.Concat(Enumerable.Repeat(" }", depth));
+
+        var document = Utf8GraphQLParser.Parse(query, options);
+
+        Assert.NotNull(document);
+        Assert.Single(document.Definitions);
+    }
+
+    [Theory]
+    [InlineData(20_000)]
+    [InlineData(50_000)]
+    public void Reject_Attack_Payload_Nested_Selection_Sets(int depth)
+    {
+        var query = string.Concat(Enumerable.Repeat("{ a", depth))
+            + string.Concat(Enumerable.Repeat(" }", depth));
+
+        Assert.Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query));
+    }
+
+    [Theory]
+    [InlineData(20_000)]
+    [InlineData(50_000)]
+    public void Reject_Attack_Payload_Nested_List_Values(int depth)
+    {
+        var query = "{ a(x: "
+            + string.Concat(Enumerable.Repeat("[", depth))
+            + "1"
+            + string.Concat(Enumerable.Repeat("]", depth))
+            + ") }";
+
+        Assert.Throws<SyntaxException>(() => Utf8GraphQLParser.Parse(query));
+    }
+
+    [Fact]
+    public void Default_MaxAllowedDirectives_Is_4()
+    {
+        Assert.Equal(4, ParserOptions.Default.MaxAllowedDirectives);
+    }
+
+    [Fact]
+    public void Reject_Fields_Exceeding_Max_Allowed_Directives_Per_Location()
+    {
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse("{ a @d @d @d @d @d }"))
+            .Message
+            .MatchInlineSnapshot(
+                "A location in the GraphQL document contains more than 4 directives. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Allow_Fields_Within_Max_Allowed_Directives_Per_Location()
+    {
+        Utf8GraphQLParser.Parse("{ a @d @d @d @d }");
+    }
+
+    [Fact]
+    public void Reject_Fields_Exceeding_Custom_Directive_Limit()
+    {
+        var options = new ParserOptions(
+            noLocations: false,
+            allowFragmentVariables: false,
+            maxAllowedNodes: int.MaxValue,
+            maxAllowedTokens: int.MaxValue,
+            maxAllowedFields: 2048,
+            maxAllowedDirectives: 2,
+            maxAllowedRecursionDepth: 200);
+
+        Assert
+            .Throws<SyntaxException>(() => Utf8GraphQLParser.Parse("{ a @d @d @d }", options))
+            .Message
+            .MatchInlineSnapshot(
+                "A location in the GraphQL document contains more than 2 directives. Parsing aborted.");
+    }
+
+    [Fact]
+    public void Allow_Fields_Within_Custom_Directive_Limit()
+    {
+        var options = new ParserOptions(
+            noLocations: false,
+            allowFragmentVariables: false,
+            maxAllowedNodes: int.MaxValue,
+            maxAllowedTokens: int.MaxValue,
+            maxAllowedFields: 2048,
+            maxAllowedDirectives: 2,
+            maxAllowedRecursionDepth: 200);
+        Utf8GraphQLParser.Parse("{ a @d @d }", options);
+    }
+
     [Fact]
     public void Reject_Queries_With_More_Than_2048_Fields()
     {;