Improper Authentication in Traefik - #VU144551
Published: August 21, 2026
Vulnerability identifier: #VU144551
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass client-certificate authentication.
The vulnerability exists due to improper authentication in the Kubernetes Ingress NGINX provider when processing multiple HTTPS Ingress objects for the same host with different generated TLS option names. A remote attacker can access a route without presenting a client certificate to bypass client-certificate authentication.
The issue occurs when the same host is split across multiple Ingress objects that use the same client CA secret and client-authentication mode, causing Traefik to treat TLS option selection as ambiguous and fall back to the default TLS configuration.
Affected software
Traefik
Remediation
Install security update from vendor's website.
Traefik - update to 3.7.11