Node.js TLS clientcert auth bypass via SNI renegotiation (v2226)
CVE-2026-123872 Published on November 11, 2026
Node.js is vulnerable to a client certificate authentication bypass via TLS 1.2 renegotiation servername change
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.
Weakness Type
What is an authentification Vulnerability?
When an actor claims to have a given identity, the software does not prove or insufficiently proves that the claim is correct.
CVE-2026-123872 has been classified to as an authentification vulnerability or weakness.
Affected Versions
nodejs node:- Version 0.0.0 and below 22.23.5 is affected.
- Version 23.0.0 and below 24.22.3 is affected.
- Version 25.0.0 and below 26.13.1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.