ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-118666

GraphQL Tools: Shared legacy executor routes one subscription's results to a different caller

Published Oct 28, 2026 · GraphQL Tools: Shared legacy

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-118666. EPSS is 0.34%. Act only if a listed version of GraphQL Tools: Shared legacy is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (GraphQL Tools: Shared legacy).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.34%
Remediation
Not established
Affected products
npm @graphql-tools

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • npm @graphql-toolsversion unspecified

How to fix CVE-2026-118666

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-118666. EPSS is 0.34%. Act only if a listed version of GraphQL Tools: Shared legacy is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.34%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 28, 2026 · GitLab Advisory Database

    Detected

    buildWSLegacyExecutor keeps one WebSocket in closure state and installs the message handler by assigning to the socket's single websocket.onmessage property inside subscribe(). Every new subscription therefore overwrites the previous subscriber's handler, and the handler's case LEGACY_WS.DATA branch calls observer.next(data.payload) without ever comparing data.id to the operation id that this subs

Sources

  • CVE.orgVulnerability recordCVE-2026-118666

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-118666

    30-day exploitation probability 0.34%

    first.org
  • GitLab Advisory DatabasePackage advisoryCVE-2026-118666

    buildWSLegacyExecutor keeps one WebSocket in closure state and installs the message handler by assigning to the socket's single websocket.onmessage property inside subscribe(). Every new subscription therefore overwrites the previous subscriber's handler, and the handler's case LEGACY_WS.DATA branch calls observer.next(data.payload) without ever comparing data.id to the operation id that this subs

    advisories.gitlab.com
  • Tenable CVE DatabaseVulnerability recordCVE-2026-118666

    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

    tenable.com

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 7, 2026
  • Tenable CVE DatabaseNov 3, 2026
  • GitLab Advisory DatabaseOct 30, 2026
  • CVE.orgOct 29, 2026