Vulnerability · Published Aug 1, 2026 · Assigned by VulnCheck
CVE-2026-67309Traefik v3.7.0 Path Traversal via RewriteTarget Authentication Bypass
High 7.8
In plain English
A high-severity path traversal in traefik from traefik. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Traefik versions >= v3.7.0 and <= v3.7.7 contain a path traversal vulnerability in the Kubernetes Ingress NGINX provider's RewriteTarget middleware (generated from the nginx.ingress.kubernetes.io/rewrite-target annotation). When an Ingress path uses a regex that captures attacker-controlled text without requiring a path separator (e.g., path /api(.*) with rewrite target /$1), a crafted request such as /api../admin matches the public router, is rewritten to a dot-segment traversal path (/../admin), and is forwarded without post-replacement normalization validation. A backend that normalizes dot segments resolves the path to a protected endpoint (e.g., /admin) reachable only through a separate router secured with BasicAuth, DigestAuth, or ForwardAuth, resulting in route-level authentication bypass. The issue is fixed in v3.7.8.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/traefik/traefik | no fix listed | GO-2026-6207 |
| Go | github.com/traefik/traefik/v2 | no fix listed | GO-2026-6207 |
| Go | github.com/traefik/traefik/v3 | 3.7.8 | GHSA-8rxv-jg7p-wvg3 |
| Go | github.com/traefik/traefik/v3 | 3.7.8 | GO-2026-6207 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
References
- GitHub Security Advisory (GHSA-8rxv-jg7p-wvg3) vendor-advisory
- Patch Commit patch
- Patch Commit patch
- VulnCheck Advisory: Traefik v3.7.0 Path Traversal via RewriteTarget Authentication Bypass third-party-advisory