Auth bypass in Traefik
CVE-2026-114639
Traefik 2.11.0 before 2.11.58 and 3.0.0 before 3.7.14 contains an authentication bypass because a first request preauthenticated with an Authorization: Negotiate token authenticates a socket in the globally shared backend connection pool, which is never isolated. Unauthenticated attackers on separate frontend connections can be assigned that NTLM/Kerberos-bound socket and perform reads or writes with the victim's identity.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/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
Weakness classification (CWE)
References
- github.com/traefik/traefik/security/advisories/GHSA-qm9f-w54v-q2qh (vendor-advisory)
- www.vulncheck.com/advisories/traefik-before-2.11.58-and-3.7.14-authentication-b… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-114639?
- CVE-2026-114639 is a high-severity vulnerability in Traefik, classified under Improper Authentication. CVSS score: 8.7/10. Published 2026-10-22.
- How severe is CVE-2026-114639?
- High severity. CVSS v3 base score is 8.7 out of 10.