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Vulnerability record · CVE-2026-85596 · published 4 September 2026

CVE-2026-85596: Traefik improper authentication vulnerability

Traefik · Traefik

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.

8.2 CVSS 4.0 High EPSS 0.43% · top 64.7% CWE-287 · Improper authentication
8.2CVSS 4.0 base score
0.43%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 1 tagged exploit
16 Sep 2026Last modified by NVD

Description

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.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq ExploitMitigationPatchVendor Advisory
https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict Third Party Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-85596), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.