# CVE-2026-103921: GraphQL Tools: TLS Certificate Validation Disabled in Legacy GraphQL WebSocket Executor

> A network attacker can intercept GraphQL WebSocket connections to steal authentication tokens and modify subscription data due to disabled TLS certificate validation.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Oct 2026
- **Updated:** 1 Oct 2026
- **Also known as:** CLSA-2026-1793113102, GHSA-6fw5-9hq8-w87g, ROOT-APP-NPM-CVE-2026-103921

## What is CVE-2026-103921?

CVE-2026-103921 is a high-severity vulnerability in @graphql-tools executor-legacy-ws, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to 1.1.35, the executor-legacy-ws buildWSLegacyExecutor() function hardcodes TLS certificate rejection off for Node.js connections to wss:// endpoints. Applications using the executor directly, or url-loader with SubscriptionProtocol.LEGACY_WS, can therefore accept an attacker-controlled certificate when a network-positioned attacker intercepts the connection. Authentication material in connectionParams or headers can be disclosed, and subscription data can be modified. Browser WebSocket clients are unaffected because browsers enforce certificate validation. This issue is fixed in version 1.1.35.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-103921?

2 open source packages ship an affected version, including @graphql-tools/executor-legacy-ws.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@graphql-tools/executor-legacy-ws` | npm | All versions | 1.1.35 |
| `@graphql-tools/executor-legacy-ws` | npm | All versions | 1.1.35 |

## How do I fix CVE-2026-103921?

Upgrade @graphql-tools/executor-legacy-ws to 1.1.35 or later.

## Is CVE-2026-103921 being exploited?

There is no known exploitation of CVE-2026-103921 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103921 and fix it if it is affected.

What it is: CVE-2026-103921 is a high-severity vulnerability in @graphql-tools executor-legacy-ws, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-103921 in the wild and no public exploit code.

Affected packages and fixed versions:
- @graphql-tools/executor-legacy-ws (npm): affected all versions; fixed in 1.1.35
- @graphql-tools/executor-legacy-ws (npm): affected all versions; fixed in 1.1.35

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-103921/ (Markdown: https://insights.sbomify.com/CVE-2026-103921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103921
- OSV: https://osv.dev/vulnerability/CVE-2026-103921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103921/
Summaries are generated and may contain mistakes; the official description above is the record.