Vulnerability Description
GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to version 1.1.36 of the GraphQL Tools legacy WebSocket executor package, buildWSLegacyExecutor in packages/executors/legacy-ws/src/index.ts reuses one WebSocket and replaces its single websocket.onmessage handler whenever a new overlapping subscription starts. The handler delivers LEGACY_WS.DATA frames to the newest observer without comparing data.id with the subscription operation id, so a caller using the same executor can receive another user's authorized subscription payload while the earlier caller's stream is starved. This issue is fixed in version 1.1.36 of the GraphQL Tools legacy WebSocket executor package.
Related Weaknesses (CWE)
References
- https://github.com/ardatan/graphql-tools/commit/c2f226e6f68236be9e4a577f29faeaa9
- https://github.com/ardatan/graphql-tools/pull/8480
- https://github.com/ardatan/graphql-tools/releases/tag/@graphql-tools/executor-le
- https://github.com/ardatan/graphql-tools/security/advisories/GHSA-mp66-8ww2-pcwm
FAQ
What is CVE-2026-118666?
CVE-2026-118666 is a documented vulnerability. GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to version 1.1.36 of the GraphQL Tools legacy WebSocket executor package, buildWSLegacyExecutor in packages...
How severe is CVE-2026-118666?
CVSS scoring is not yet available for CVE-2026-118666. Check NVD for updates.
Is there a patch for CVE-2026-118666?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.