{"id":"CVE-2026-75507","title":"GraphQL-core: Denial of service via quadratic complexity in the OverlappingFieldsCanBeMerged validation rule","summary":"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…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-400","CWE-407"],"vendor":"graphql-python","product":"graphql-core","affected":["graphql-core >= 3.0.0, < 3.2.12","graphql-core >= 3.3.0a1, < 3.3.0rc1"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-23T17:32:54.760212Z"},"published":"2026-10-22","updated":"2026-10-23","sourceUpdated":"2026-10-23T21:08:40.217Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-75507","references":[{"url":"https://github.com/graphql-python/graphql-core/security/advisories/GHSA-vj8h-fx38-h3vc","label":"https://github.com/graphql-python/graphql-core/security/advisories/GHSA-vj8h-fx38-h3vc"},{"url":"https://github.com/graphql-python/graphql-core/commit/150e59814d97d12140be005a558c93188ef89198","label":"https://github.com/graphql-python/graphql-core/commit/150e59814d97d12140be005a558c93188ef89198"},{"url":"https://github.com/graphql-python/graphql-core/commit/29c2753a7ee30a96a4109e7c6add1a2dae0497d7","label":"https://github.com/graphql-python/graphql-core/commit/29c2753a7ee30a96a4109e7c6add1a2dae0497d7"},{"url":"https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12","label":"https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12"},{"url":"https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1","label":"https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1"},{"url":"https://github.com/graphql-python/graphql-core"},{"url":"https://github.com/advisories/GHSA-vj8h-fx38-h3vc"}],"tags":["cve.org","osv","pip","ghsa"],"epss":0.006,"epssPercentile":0.48503,"aliases":["GHSA-vj8h-fx38-h3vc"],"ecosystem":"pip","patched":["graphql-core 3.2.12","graphql-core 3.3.0rc1"],"ingestedAt":"2026-10-22T22:00:50.254Z","slug":"CVE-2026-75507","body":"## Overview\n\nGraphQL-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.\n\n## Affected\n\n- `graphql-core >= 3.0.0, < 3.2.12`\n- `graphql-core >= 3.3.0a1, < 3.3.0rc1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-75507)\n\nAffected packages:\n\n- `graphql-core >= 3.0.0, < 3.2.12`\n- `graphql-core >= 3.3.0a1, < 3.3.0rc1`\n\nPatched in:\n\n- `graphql-core 3.2.12`\n- `graphql-core 3.3.0rc1`\n\nSource: https://osv.dev/vulnerability/GHSA-vj8h-fx38-h3vc","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}