# CVE-2026-75507: graphql-core: GraphQL-core is a Python port of the GraphQL.js reference implementation

CVE-2026-75507 is fixed in graphql-core on 1 platform by DEBIAN-CVE-2026-75507 (version 3.2.12-1), released October 24, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-75507
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0080
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 22, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | graphql-core Debian 14 | 3.2.12-1 | [DEBIAN-CVE-2026-75507](https://patchblox.com/security/data/fix/linux/debian-cve-2026-75507.md) | Oct 24, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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