[ CVE-2026-118666 · Published 28 Oct 2026 ]
GraphQL Tools: Shared legacy executor routes one subscription's results to a different caller
[ Why it matters ]Priority signals
- Public proof-of-concept exploit exists (CISA SSVC)
[ Description ]Official 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.
[ Fixes ]Fixes and patches
- @graphql-tools/executor-legacy-ws 1.1.36Fixed version · GitHub Advisories · npm package @graphql-tools/executor-legacy-ws: upgrade to 1.1.36 or later (affected <= 1.1.35)
[ Packages ]Affected open-source packages
- @graphql-tools/executor-legacy-ws npmAffected <= 1.1.35 · fixed in 1.1.36 · GHSA-mp66-8ww2-pcwm