CVE-2026-123867
Publication date 12 November 2026
Last updated 13 November 2026
Ubuntu priority
Description
A per-host mutual-TLS authorization bypass in Node.js lets a client authorized for the default hostname reach a protected hostname it is not authorized for. When a TLS server assigns a hostname a different client-certificate CA with server.addContext(host, { ca: protectedCA }) but no server certificate in that SNI context, the per-host client CA is never installed and the handshake falls back to the default client CA. In src/crypto/crypto_tls.cc, CertCbDone installs the SNI context's CA only when setSniContext succeeds, but setSniContext returns false for a context with no server certificate, so a CA-only SNI context silently keeps the default CA. A client holding a certificate trusted by the default CA, but not the protected CA, can therefore complete mTLS to the protected hostname and read its response even with requestCert and rejectUnauthorized enabled, while a client certified by the protected CA is rejected. 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
4.2 · Medium
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-123867
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases#ca-only-sni-client-ca-overrides-fail-open-to-the-default-ca-bypassing-per-host-mtls-authorization-cve-2026-123867---medium
- https://cna.openjsf.org/security-advisories.html
- https://nodejs.org/en/blog/vulnerability/november-2026-security-releases