What is CVE-2026-103921?

CVE-2026-103921 is a high-severity vulnerability in Ardatan Graphql-Tools, classified under Improper Certificate Validation. CVSS score: 7.4/10. Published 2026-10-01.

How severe is CVE-2026-103921?

High severity. CVSS v3 base score is 7.4 out of 10.

Vulnerability in Ardatan Graphql-Tools

CVE-2026-103921

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.

Vulnerability class: Improper Certificate Validation

Published 2026-10-01 · last modified 2026-10-01.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Ardatan Graphql-Tools — versions < 1.1.35
@Graphql-Tools Executor-Legacy-Ws — versions < 1.1.35

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

Frequently asked questions

What is CVE-2026-103921?: CVE-2026-103921 is a high-severity vulnerability in Ardatan Graphql-Tools, classified under Improper Certificate Validation. CVSS score: 7.4/10. Published 2026-10-01.
How severe is CVE-2026-103921?: High severity. CVSS v3 base score is 7.4 out of 10.