Auth bypass in Traefik
CVE-2026-65601
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.
Vulnerability class: Broken Access Control
EPSS: 0.003 (21.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Traefik — versions 3.7.0, 3.7.7
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory, Vendor Advisory)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-65601?
- CVE-2026-65601 is a high-severity vulnerability in Traefik, classified under Incorrect Authorization. CVSS score: 8.8/10. Published 2026-07-22.
- How severe is CVE-2026-65601?
- High severity. CVSS v3 base score is 8.8 out of 10.