Path Traversal in Traefik
CVE-2026-65600
Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6 contain an authentication bypass via path traversal in the ReplacePathRegex middleware. When ReplacePathRegex is configured with a regex that captures user-controlled path segments without a mandatory path separator (e.g. regex "^/api(.*)", replacement "/$1"), the middleware forwards the replaced path to the backend without validating that it matches its normalized form. An unauthenticated remote attacker can send a crafted request (e.g. GET /api../admin) that produces an un-normalized path such as /../admin, which a backend that normalizes paths resolves to a protected route, bypassing authentication middleware. Fixed in v2.11.52, v3.6.23, and v3.7.7.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.004 (34.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Traefik — versions 0, 2.11.52, 3.6.0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory, Patch, Vendor Advisory)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-65600?
- CVE-2026-65600 is a medium-severity vulnerability in Traefik, classified under Path Traversal. CVSS score: 5.3/10. Published 2026-07-22.
- How severe is CVE-2026-65600?
- Medium severity. CVSS v3 base score is 5.3 out of 10.