CVE-2026-75507
GraphQL-core: Denial of service via quadratic complexity in the OverlappingFieldsCanBeMerged validation rule
Impact
GraphQL-core is a Python port of the GraphQL.js reference implementation. From 3.0.0 until 3.2.12 and 3.3.0rc1, the OverlappingFieldsCanBeMerged rule in specified_rules repeatedly compares fields that share response names and recursively re-compares flattened inline fragments during the validation phase. The prior named-fragment memoization does not cover this path, so nested repeated inline fragments can drive quadratic and worst-case O(n²·m²) CPU work before any resolver or AST-based depth or complexity control runs. An unauthenticated remote attacker can submit a shallow, highly compressible GraphQL query that pins a worker process and can saturate a multi-worker service. This issue is fixed in versions 3.2.12 and 3.3.0rc1.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | graphql-core | >= 3.0.0, < 3.2.12 | 3.2.12 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-vj8h-fx38-h3vc
- https://github.com/graphql-python/graphql-core/security/advisories/GHSA-vj8h-fx38-h3vc
- https://github.com/graphql-python/graphql-core/commit/150e59814d97d12140be005a558c93188ef89198
- https://github.com/graphql-python/graphql-core/commit/29c2753a7ee30a96a4109e7c6add1a2dae0497d7
- https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12
- https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1