Description
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.
References5
- github.com/graphql-python/graphql-core/commit/150e59814d97d1214…
- github.com/graphql-python/graphql-core/commit/29c2753a7ee30a96a…
- github.com/graphql-python/graphql-core/releases/tag/v3.2.12
- github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1
- github.com/graphql-python/graphql-core/security/advisories/GHSA…
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 57 · as of 8 November 2026
- CWE
- CWE-400CWE-407
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.