CVE-2026-75508
GraphQL-core: Denial of service via comment tokens bypassing the parser's max_tokens limit
- State
- Published
- Severity
- 7.5 High
- Published
- Oct 22, 2026
- Updated
- Oct 29, 2026
- Reserved
- Aug 17, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
graphql-coregraphql-python |
|
References
- https://github.com/graphql-python/graphql-core/security/advisories/GHSA-r77w-qph3-7vf8
- 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
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