Vulnerability Description
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a potential vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing the documented isolation boundary. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Traefik | Traefik | < 2.11.43 |
Related Weaknesses (CWE)
References
- https://github.com/traefik/traefik/commit/df00d82fc7f12e07199551832b54de6d0e5541Patch
- https://github.com/traefik/traefik/releases/tag/v2.11.43ProductRelease Notes
- https://github.com/traefik/traefik/releases/tag/v3.6.14ProductRelease Notes
- https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2ProductRelease Notes
- https://github.com/traefik/traefik/security/advisories/GHSA-xhjw-95fp-8vgqExploitPatchVendor Advisory
FAQ
What is CVE-2026-41174?
CVE-2026-41174 is a vulnerability with a CVSS score of 6.4 (MEDIUM). Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a potential vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation...
How severe is CVE-2026-41174?
CVE-2026-41174 has been rated MEDIUM with a CVSS base score of 6.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-41174?
Check the references section above for vendor advisories and patch information. Affected products include: Traefik Traefik.