Vulnerability · Published Oct 22, 2026 · Assigned by GitHub_M
CVE-2026-75507GraphQL-core: Denial of service via quadratic complexity in the OverlappingFieldsCanBeMerged validation rule
High 7.5
In plain English
A high-severity uncontrolled resource consumption in graphql-core from graphql-python. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | graphql-core | no fix listed | DEBIAN-CVE-2026-75507 |
| Debian:13 | graphql-core | no fix listed | DEBIAN-CVE-2026-75507 |
| Debian:14 | graphql-core | 3.2.12-1 | DEBIAN-CVE-2026-75507 |
| PyPI | graphql-core | 3.2.12 | GHSA-vj8h-fx38-h3vc |
| PyPI | graphql-core | 3.3.0rc1 | GHSA-vj8h-fx38-h3vc |
| Ubuntu:22.04:LTS | graphql-core | no fix listed | UBUNTU-CVE-2026-75507 |
| Ubuntu:24.04:LTS | graphql-core | no fix listed | UBUNTU-CVE-2026-75507 |
| Ubuntu:26.04:LTS | graphql-core | no fix listed | UBUNTU-CVE-2026-75507 |
| Ubuntu:26.10 | graphql-core | no fix listed | UBUNTU-CVE-2026-75507 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| graphql-python | graphql-core | >= 3.0.0, < 3.2.12>= 3.3.0a1, < 3.3.0rc1 |
Weakness: CWE-400, CWE-407 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/graphql-python/graphql-core/security/advisories/GHSA-vj8h-fx38-h3vc x_refsource_CONFIRM
- https://github.com/graphql-python/graphql-core/commit/150e59814d97d12140be005a558c93188ef89198 x_refsource_MISC
- https://github.com/graphql-python/graphql-core/commit/29c2753a7ee30a96a4109e7c6add1a2dae0497d7 x_refsource_MISC
- https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12 x_refsource_MISC
- https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1 x_refsource_MISC