Path traversal in Traefik - #VU137266
Published: July 9, 2026
Vulnerability identifier: #VU137266
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Containous
Affected software:
Traefik
Traefik
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass authentication and access protected routes.
The vulnerability exists due to path traversal in ReplacePathRegex middleware when processing a crafted HTTP request that produces an un-normalized replacement path. A remote attacker can send a specially crafted request to bypass authentication and access protected routes.
The issue occurs only when ReplacePathRegex is configured with a regular expression that captures user-controlled path segments without a mandatory separator, and exploitation depends on a backend that normalizes the forwarded path.
Remediation
Install security update from vendor's website.