Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Traefik | Traefik | < 2.11.52 |
Related Weaknesses (CWE)
References
- https://github.com/traefik/traefik/security/advisories/GHSA-cxjq-mrr5-89rvVendor AdvisoryPatch
- https://www.vulncheck.com/advisories/traefik-before-authentication-bypass-via-reThird Party Advisory
FAQ
What is CVE-2026-65600?
CVE-2026-65600 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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 ...
How severe is CVE-2026-65600?
CVE-2026-65600 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-65600?
Check the references section above for vendor advisories and patch information. Affected products include: Traefik Traefik.