GraphQL Tools: TLS Certificate Validation Disabled in Legacy GraphQL WebSocket Executor

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.4 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

• CVE-2026-103921: 0.27% estimated exploitation activity in the next 30 days; percentile 19.80 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact buildWSLegacyExecutor() in @graphql-tools/executor-legacy-ws previously hardcoded rejectUnauthorized: false when creating WebSocket connections over WSS. This disabled TLS certificate validation, allowing a network-positioned attacker to perform a Man-in-the-Middle (MITM) attack against applications that use this executor with a wss:// endpoint. Credentials passed via connectionParams or headers could be intercepted, and subscription data could be tampered with. Who is impacted: Applications using @graphql-tools/executor-legacy-ws (directly or via @graphql-tools/url-loader with SubscriptionProtocol.LEGACYWS) to connect to a wss:// endpoint from Node.js while sending authentication material over the connection. Browser WebSocket clients are unaffected by this option (browsers always validate certificates). Patches Upgrade to @graphql-tools/executor-legacy-ws@1.1.35 or later (and @graphql-tools/url-loader@9.1.9 or later if you use the loader). TLS certificate validation is…

Published by the source

5 Oct 2026, 22:56 UTC

Last modified by the source

5 Oct 2026, 23:15 UTC

Source last checked

26 Oct 2026, 13:06 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-6fw5-9hq8-w87g

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-6fw5-9hq8-w87g

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-6fw5-9hq8-w87g

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-103921

Advisory: GraphQL Tools: TLS Certificate Validation Disabled in Legacy GraphQL WebSocket Executor
IDs: CVE-2026-103921, GHSA-6fw5-9hq8-w87g
Record: https://patchnext.com/advisories/cve-2026-103921 (revision 3, source checked 26 Oct 2026, 13:06 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @graphql-tools/executor-legacy-ws 1.1.35. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @graphql-tools/executor-legacy-ws: affected <= 1.1.34; fixed in 1.1.35

## Suggested inspection (read-only)
- `npm ls @graphql-tools/executor-legacy-ws --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @graphql-tools/executor-legacy-ws.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6fw5-9hq8-w87g (GitHub-reviewed advisory GHSA-6fw5-9hq8-w87g lists affected ranges: npm @graphql-tools/executor-legacy-ws >=0 <=1.1.34)
- Verified: https://osv.dev/vulnerability/GHSA-6fw5-9hq8-w87g (OSV record GHSA-6fw5-9hq8-w87g lists affected ranges: npm @graphql-tools/executor-legacy-ws >=0 <1.1.35 (fixed))

Commands are suggestions: review each one before running it.