CVE-2026-85596CWE-287

CVE-2026-85596

Critical · published September 4, 2026

CVSS v3.1
9.8
EPSS
0%
Percentile
36.8
In the wild
Unconfirmed
What it is

Traefik versions >= v3.7.0 and <= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/auth-tls-secret annotation was named after the Ingress namespace and name. As a result, two Ingress objects sharing the same host, the same client CA secret, and the same client-authentication mode produced two distinct TLS option names for that host. Traefik treats this as a TLS options conflict and falls back to the entry point's default TLS configuration, which does not request a client certificate, so a route configured with nginx.ingress.kubernetes.io/auth-tls-verify-client: "on" becomes reachable without a client certificate. Only the v3.7 line is affected; the issue is fixed in v3.7.11.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
8.2 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
EPSS
0.00435 · 36.8th percentile
Weakness
CWE-287 · Improper Authentication
Published
2026-09-04T16:17Z
Affected products (1)
ProductVersionsFixed in
traefik/traefik≥ 3.7.0, < 3.7.113.7.11
References (2)
EPSS history
Timeline
  • 06 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 04 SEP 11:30Z
    Traefik v3.7 Authentication Bypass via TLS Option Conflict
    cvelistv5