CVE-2026-41174
CVE-2026-41174 · Traefik Kubernetes CRD allows unauthorized cross-namespace middleware binding
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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 4.8 · Medium · EPSS 0.3%
- Published
- Updated
Stack: web
Affected products and versions
traefik
- Versions
- < 2.11.43: Affected
- >= 3.7.0-ea.1, < 3.7.0-rc.2: Affected
No fix published
Original sources
- https://github.com/traefik/traefik/security/advisories/GHSA-xhjw-95fp-8vgq
- https://github.com/traefik/traefik/commit/df00d82fc7f12e07199551832b54de6d0e55414d
- https://github.com/traefik/traefik/releases/tag/v2.11.43
- https://github.com/traefik/traefik/releases/tag/v3.6.14
- https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2
- https://nvd.nist.gov/vuln/detail/CVE-2026-41174