Traefik v3.7 Authentication Bypass via TLS Option Conflict
Published Sep 4, 2026
8.2
HIGHCVSS 4.0
EPSS 0.43%
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.
Affected products
-
- Version 3.7.0StatusaffectedConstraints<=3.7.10
- Version
No data.
Red Hat OpenShift Dev Spaces
devspaces/traefik-rhel9
Not affected
Red Hat OpenShift GitOps
openshift-gitops-1/argo-rollouts-rhel8
Not affected
Red Hat OpenShift GitOps
openshift-gitops-1/argo-rollouts-rhel9
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat OpenShift Dev Spaces | devspaces/traefik-rhel9 | Not affected | n/a |
| Red Hat OpenShift GitOps | openshift-gitops-1/argo-rollouts-rhel8 | Not affected | n/a |
| Red Hat OpenShift GitOps | openshift-gitops-1/argo-rollouts-rhel9 | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
A flaw was found in Traefik's Kubernetes Ingress NGINX provider (v3.7.0 through v3.7.10) where TLS options generated for Ingress objects using the auth-tls-secret annotation are incorrectly named using the namespace and Ingress name. When multiple Ingress objects share the same host, client CA secret, and authentication mode, Traefik misinterprets the resulting distinct TLS option names as a configuration conflict. This causes Traefik to regress to default entrypoint TLS options that do not request client certificates, allowing remote unauthenticated attackers to bypass mTLS requirements on routes protected by auth-tls-verify-client.
Red Hat mitigation
Consolidate Ingress rules sharing the same host and client CA secret into a single Ingress resource, or avoid using the auth-tls-secret annotation across multiple distinct Ingress objects for a shared host. Alternatively, enforce client certificate validation at an upstream load balancer or API gateway until patched.
Metrics
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
1 other source (NVD) ▾
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:X/V:X/RE:X/U:X
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Sep 10, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
Sep–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 0.43% (0.00435) | 35.60th | v5 (v2026.06.15) |
| Sep 5, 2026 | 0.22% (0.00224) | 12.97th | v5 (v2026.06.15) |
References (6)
- https://access.redhat.com/security/cve/CVE-2026-85596 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2529028 Issue Tracking
- https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq vendor-advisoryExploitMitigationPatchVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-85596
- https://www.cve.org/CVERecord?id=CVE-2026-85596
- https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict third-party-advisoryThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2026-85596 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2529028 | Issue Tracking | |
| https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwq | vendor-advisoryExploitMitigationPatchVendor Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-85596 | ||
| https://www.cve.org/CVERecord?id=CVE-2026-85596 | ||
| https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-option-conflict | third-party-advisoryThird Party Advisory |
Change history (0)
No recorded changes yet.