# CVE-2026-103921: GraphQL Tools executor-legacy-ws TLS certificate validation bypass

Source: https://junglewise.ai/threats/cve-2026-103921-graphql-tools-provides-utilities-for-building-stitching-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-01. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-103921 · Severity: high · CVSS 7.4 · Published 2026-10-01

GraphQL Tools is a library for building and managing GraphQL schemas. The executor-legacy-ws component disabled TLS certificate validation on WebSocket connections, allowing a network attacker to intercept connections and steal authentication credentials or modify subscription data. The vulnerability only affects Node.js applications; web-based clients are unaffected. The issue is fixed in version 1.1.35.

Technologies: [@graphql-tools/executor-legacy-ws (npm)](https://junglewise.ai/threats/technologies/graphql-tools-executor-legacy-ws). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-103921 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103921 being exploited in the wild.

**How severe is CVE-2026-103921?** High severity, with a CVSS score of 7.4, published 1 October 2026.

**Which products and versions are affected?** Ardatan Graphql-Tools before 1.1.35; @graphql-tools/executor-legacy-ws (npm) <= 1.1.34, SEMVER:introduced=0,fixed=1.1.35.

**Is there a fix for CVE-2026-103921?** Yes. @graphql-tools/executor-legacy-ws (npm): upgrade to 1.1.35 or later. Until then: For self-signed or trusted internal certificate environments that require the legacy behavior, the fix exposes a rejectUnauthorized opt-out configuration option to allow accepting self-signed certificates. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-103921 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-103921?** Check whether you run Ardatan Graphql-Tools or @graphql-tools/executor-legacy-ws (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @graphql-tools/executor-legacy-ws (npm): upgrade to 1.1.35 or later

  ```sh
  npm install @graphql-tools/executor-legacy-ws@1.1.35
  ```


For self-signed or trusted internal certificate environments that require the legacy behavior, the fix exposes a rejectUnauthorized opt-out configuration option to allow accepting self-signed certificates.

## Technical details

The buildWSLegacyExecutor() function hardcoded rejectUnauthorized:false, disabling TLS certificate validation on wss:// connections in a way that could not be overridden by callers. An attacker positioned on the network can perform MITM attacks to intercept credentials passed in connectionParams or headers and modify subscription data. The vulnerability affects applications using the executor directly or via url-loader with SubscriptionProtocol.LEGACY_WS; browser WebSocket clients are unaffected due to browser-enforced validation.

## Affected products

- ardatan graphql-tools before 1.1.35

## Identifiers

- CVE-2026-103921
- GHSA-6fw5-9hq8-w87g

## Timeline

- 2026-10-01: disclosed
- 2026-09-08: patched

## References

- [https://github.com/ardatan/graphql-tools/commit/3831a0661514c91d99971052f983552556880402](https://github.com/ardatan/graphql-tools/commit/3831a0661514c91d99971052f983552556880402)
- [https://github.com/ardatan/graphql-tools/pull/8426](https://github.com/ardatan/graphql-tools/pull/8426)

## Related threats

- [GraphQL Tools legacy WebSocket executor data and auth isolation flaw](https://junglewise.ai/threats/cve-2026-118666-graphql-tools-provides-utilities-for-building-stitching-and)
- [GraphQL Tools legacy WebSocket executor auth context isolation](https://junglewise.ai/threats/cve-2026-118665-graphql-tools-provides-utilities-for-building-stitching-and)