Description
A client certificate authentication bypass in Node.js TLS lets a client change the servername during TLS 1.2 renegotiation to reach endpoints it was not authorized for. On a server that applies different client-certificate policies per hostname, for example stricter admin-only client-cert auth on one host and ordinary client-cert auth on another, a client that authenticates for a permitted host can renegotiate the TLS 1.2 connection under a different servername and carry its existing authentication to the protected host, bypassing the stricter policy. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Published: 2026-11-11
Score: 8.1 High
EPSS: < 1% Very Low
KEV: No
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Thu, 12 Nov 2026 18:45:00 +0000

Type Values Removed Values Added
First Time appeared Nodejs
Nodejs nodejs
Vendors & Products Nodejs
Nodejs nodejs

Thu, 12 Nov 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-295
References
Metrics threat_severity

None

cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

threat_severity

Important


Wed, 11 Nov 2026 18:45:00 +0000

Type Values Removed Values Added
Description A client certificate authentication bypass in Node.js TLS lets a client change the servername during TLS 1.2 renegotiation to reach endpoints it was not authorized for. On a server that applies different client-certificate policies per hostname, for example stricter admin-only client-cert auth on one host and ordinary client-cert auth on another, a client that authenticates for a permitted host can renegotiate the TLS 1.2 connection under a different servername and carry its existing authentication to the protected host, bypassing the stricter policy. This vulnerability affects Node.js 26.x, 24.x, and 22.x.
Title Node.js is vulnerable to a client certificate authentication bypass via TLS 1.2 renegotiation servername change
Weaknesses CWE-287
References
Metrics cvssV3_0

{'score': 8.1, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: openjs

Published:

Updated: 2026-11-11T18:30:25.193Z

Reserved: 2026-11-06T16:19:31.993Z

Link: CVE-2026-123872

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-11T19:17:34.270

Modified: 2026-11-12T19:02:35.830

Link: CVE-2026-123872

cve-icon Redhat

Severity : Important

Publid Date: 2026-11-11T18:30:25Z

Links: CVE-2026-123872 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-11-12T18:30:06Z

Weaknesses
  • CWE-287

    Improper Authentication

  • CWE-295

    Improper Certificate Validation