graphql-python graphql-core up to 3.2.11 Parser Parser.advance_lexer allocation of resources

Summaryinfo

A vulnerability identified as problematic has been detected in graphql-python graphql-core up to 3.2.11. This vulnerability affects the function Parser.advance_lexer of the component Parser. This manipulation causes allocation of resources. The identification of this vulnerability is CVE-2026-75508. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in graphql-python graphql-core up to 3.2.11. It has been declared as problematic. Affected by this vulnerability is the function Parser.advance_lexer of the component Parser. The manipulation with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect availability. The summary by CVE is:

GraphQL-core is a Python port of the GraphQL.js reference implementation. From 3.2.3 until 3.2.12 and 3.3.0rc1, the parser's max_tokens limit in Parser.advance_lexer counts only non-comment tokens returned after Lexer.lookahead skips comments. Each skipped comment is still allocated as a Token and retained through token.next and token.prev, allowing a highly compressible comment-padded GraphQL document to pass a low token limit while consuming memory. An unauthenticated remote attacker can exhaust worker memory before AST-based depth or complexity controls run. This issue is fixed in versions 3.2.12 and 3.3.0rc1.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-75508 since 08/17/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 3.2.12 or 3.3.0rc1 eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• graphql-python

Name

• graphql-core

Version

• 3.2.0
• 3.2.1
• 3.2.2
• 3.2.3
• 3.2.4
• 3.2.5
• 3.2.6
• 3.2.7
• 3.2.8
• 3.2.9
• 3.2.10
• 3.2.11

Website

• Product: https://github.com/graphql-python/graphql-core/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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