CVE-2026-123872
Publication date 12 November 2026
Last updated 13 November 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| nodejs | 26.10 stonking |
Needs evaluation
|
| 26.04 LTS resolute |
Needs evaluation
|
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
|
| 14.04 LTS trusty |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
8.1 · High
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-123872
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases#tls-12-renegotiation-allows-clients-to-change-servername-unilaterally-to-bypass-client-certificate-authentication-cve-2026-123872---high
- https://cna.openjsf.org/security-advisories.html
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases