CVE-2026-75508

Description

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.

References

• https://github.com/graphql-python/graphql-core/commit/437dea102e92fdf05a2971ca76787c5a5bad875a
• https://github.com/graphql-python/graphql-core/commit/80ef435a1808fbbcc4aaac63ae76771a1c91002d
• https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12
• https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1
• https://github.com/graphql-python/graphql-core/security/advisories/GHSA-r77w-qph3-7vf8