CVE-2026-65601 PUBLISHED

Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef

Assigner: VulnCheck
Reserved: 22.07.2026 Published: 22.07.2026 Updated: 22.07.2026

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
CVSS Score: 5.3

Product Status

Vendor traefik
Product traefik
Versions Default: unaffected
  • affected from 3.7.0 to 3.7.7 (excl.)
  • Version 3.7.7 is unaffected

Credits

  • CuB3y0nd reporter

References

Problem Types

  • Incorrect Authorization CWE