Remote Code Execution vulnerability when restoring PLAIN-format SQL dumps in server mode (pgAdmin 4)

@@ -40,4 +40,5 @@ Bug fixes
   | `Issue #9233 <https://github.com/pgadmin-org/pgadmin4/issues/9233>`_ -  Fixed an issue where the Select All option on the columns tab of import/export data was not working in languages other than English.
   | `Issue #9240 <https://github.com/pgadmin-org/pgadmin4/issues/9240>`_ -  Fixed an issue where the Debian build process failed with a "Sphinx module not found" error when using a Python virtual environment.
   | `Issue #9281 <https://github.com/pgadmin-org/pgadmin4/issues/9281>`_ -  Fixed an issue where the last used storage directory was reset to blank, leading to access denied errors during backup or restore operations.
-  | `Issue #9304 <https://github.com/pgadmin-org/pgadmin4/issues/9304>`_ -  Fixed an issue that prevented assigning multiple users to an RLS policy.
\ No newline at end of file
+  | `Issue #9304 <https://github.com/pgadmin-org/pgadmin4/issues/9304>`_ -  Fixed an issue that prevented assigning multiple users to an RLS policy.
+  | `Issue #9320 <https://github.com/pgadmin-org/pgadmin4/issues/9320>`_ -  Fixed remote code execution vulnerability when restoring PLAIN-format SQL dumps in server mode (CVE-2025-12762).
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@@ -10,6 +10,7 @@
 """Implements Restore Utility"""
 
 import json
+import re
 
 from flask import render_template, request, current_app, Response
 from flask_babel import gettext as _
@@ -374,7 +375,38 @@ def use_restore_utility(data, manager, server, driver, conn, filepath):
     return None, utility, args
 
 
+def has_meta_commands(path, chunk_size=8 * 1024 * 1024):
+    """
+    Quickly detect lines starting with '\' in large SQL files.
+    Works even when lines cross chunk boundaries.
+    """
+    # Look for start-of-line pattern: beginning or after newline,
+    # optional spaces, then backslash
+    pattern = re.compile(br'(^|\n)[ \t]*\\')
+
+    with open(path, "rb") as f:
+        prev_tail = b""
+        while chunk := f.read(chunk_size):
+            data = prev_tail + chunk
+
+            # Search for pattern
+            if pattern.search(data):
+                return True
+
+            # Keep a small tail to preserve line boundary context
+            prev_tail = data[-10:]  # keep last few bytes
+
+    return False
+
+
 def use_sql_utility(data, manager, server, filepath):
+    # Check the meta commands in file.
+    if has_meta_commands(filepath):
+        return _("Restore blocked: the selected PLAIN SQL file contains psql "
+                 "meta-commands (for example \\! or \\i). For safety, "
+                 "pgAdmin does not execute meta-commands from PLAIN restores. "
+                 "Please remove meta-commands."), None, None
+
     utility = manager.utility('sql')
     ret_val = does_utility_exist(utility)
     if ret_val: