n8n is vulnerable to Python sandbox escape

@@ -179,6 +179,7 @@
 ERROR_DYNAMIC_IMPORT = (
     "Dynamic __import__() calls are not allowed for security reasons."
 )
+ERROR_MATCH_PATTERN_ATTRIBUTE = "Match pattern extracting attribute '{attr}' is disallowed, because it can be used to bypass security restrictions."
 ERROR_WINDOWS_NOT_SUPPORTED = (
     "Error: This task runner is not supported on Windows. "
     "Please use a Unix-like system (Linux or macOS)."

@@ -14,6 +14,7 @@
     ERROR_NAME_MANGLED_ATTRIBUTE,
     ERROR_DYNAMIC_IMPORT,
     ERROR_DANGEROUS_STRING_PATTERN,
+    ERROR_MATCH_PATTERN_ATTRIBUTE,
     BLOCKED_ATTRIBUTES,
     BLOCKED_NAMES,
 )
@@ -140,6 +141,17 @@ def visit_Constant(self, node: ast.Constant) -> None:
 
         self.generic_visit(node)
 
+    def visit_MatchClass(self, node: ast.MatchClass) -> None:
+        """Detect match patterns that extract blocked attributes, e.g. `case AttributeError(obj=x)`"""
+
+        for attr in node.kwd_attrs:
+            if attr in BLOCKED_ATTRIBUTES:
+                self._add_violation(
+                    node.lineno, ERROR_MATCH_PATTERN_ATTRIBUTE.format(attr=attr)
+                )
+
+        self.generic_visit(node)
+
     def _check_format_string(self, s: str, lineno: int) -> None:
         """Check if a string contains format patterns that access blocked attributes."""
 

@@ -242,6 +242,68 @@ def test_fstring_blocked_attributes_detected(self, analyzer: TaskAnalyzer) -> No
             assert "disallowed" in exc_info.value.description.lower()
 
 
+class TestMatchPatternValidation(TestTaskAnalyzer):
+    def test_match_pattern_with_blocked_attributes_blocked(
+        self, analyzer: TaskAnalyzer
+    ) -> None:
+        attempts = [
+            """
+ex = None
+try:
+    pass
+except Exception as e:
+    ex = e
+match ex:
+    case AttributeError(obj=rip):
+        pass
+""",
+            """
+match error:
+    case ValueError(obj=x):
+        pass
+""",
+            """
+match e:
+    case Exception(__traceback__=tb):
+        pass
+""",
+        ]
+
+        for code in attempts:
+            with pytest.raises(SecurityViolationError) as exc_info:
+                analyzer.validate(code)
+            assert "disallowed" in exc_info.value.description.lower()
+
+    def test_safe_match_patterns_allowed(self, analyzer: TaskAnalyzer) -> None:
+        safe_patterns = [
+            """
+match value:
+    case 1:
+        pass
+    case "hello":
+        pass
+""",
+            """
+match point:
+    case Point(x=x, y=y):
+        pass
+""",
+            """
+match data:
+    case {"key": value}:
+        pass
+""",
+            """
+match result:
+    case [first, *rest]:
+        pass
+""",
+        ]
+
+        for code in safe_patterns:
+            analyzer.validate(code)
+
+
 class TestAllowAll(TestTaskAnalyzer):
     def test_allow_all_bypasses_validation(self) -> None:
         security_config = SecurityConfig(