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.
History

Fri, 23 Oct 2026 22:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
First Time appeared Graphql-python
Graphql-python graphql-core
Weaknesses CWE-770
Vendors & Products Graphql-python
Graphql-python graphql-core
References
Metrics threat_severity

None

threat_severity

Important


Thu, 22 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title GraphQL-core: Denial of service via quadratic complexity in the OverlappingFieldsCanBeMerged validation rule
Weaknesses CWE-400
CWE-407
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-22T16:12:38.424Z

Updated: 2026-10-23T21:08:40.217Z

Reserved: 2026-08-17T20:49:21.598Z

Link: CVE-2026-75507

cve-icon Vulnrichment

Updated: 2026-10-23T17:32:55.453Z

cve-icon NVD

Status : Deferred

Published: 2026-10-22T17:16:59.757

Modified: 2026-10-23T22:17:00.110

Link: CVE-2026-75507

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-22T16:12:38Z

Links: CVE-2026-75507 - Bugzilla