CVE-2026-85594

Summary

Traefik versions from v3.7.1 fail to enforce crossProviderNamespaces restrictions on the traefik.ingress.kubernetes.io/service.middlewares Service annotation in the Kubernetes Ingress provider. A namespace-limited tenant excluded from the allowlist can attach an operator-owned middleware to its Service, and if that middleware injects backend credentials, recover them at a controlled backend.

Affected Software

VendorProductVersion RangeStatus
traefiktraefik3.7.1 <= 3.7.12affected

Weaknesses

  • CWE-639: Authorization Bypass Through User-Controlled Key

References