---
id: CVE-2026-88009
title: Traefik is an open source HTTP reverse proxy and load balancer
summary: >-
  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 eval…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N'
cwe:
  - CWE-444
  - CWE-1286
vendor: traefik
product: traefik
affected:
  - traefik < 2.11.57
  - 'traefik >= 3.0.0, < 3.7.13'
patched:
  - traefik 3.7.13
published: '2026-09-10'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T19:59:14.810'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88009'
references:
  - url: >-
      https://github.com/traefik/traefik/commit/58d1e9ca204526823211e30fd4634101c59d58e9
    label: security-advisories@github.com
  - url: 'https://github.com/traefik/traefik/pull/13796'
    label: security-advisories@github.com
  - url: 'https://github.com/traefik/traefik/releases/tag/v2.11.57'
    label: security-advisories@github.com
  - url: 'https://github.com/traefik/traefik/releases/tag/v3.7.13'
    label: security-advisories@github.com
  - url: 'https://github.com/traefik/traefik/security/advisories/GHSA-f52w-8j3h-j724'
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88009'
  - url: 'https://github.com/traefik/traefik'
tags:
  - nvd
  - cve.org
  - osv
  - go
epss: 0.0027
epssPercentile: 0.19399
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-10T15:39:54.256441Z'
scores:
  nvd: 8.2
  cna: 8.8
ingestedAt: '2026-09-13T05:29:34.871Z'
aliases:
  - GHSA-f52w-8j3h-j724
  - GO-2026-6465
ecosystem: go
---

## Overview

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.

## Affected

- `traefik < 2.11.57`
- `traefik >= 3.0.0, < 3.7.13`

## Remediation

Upgrade past the affected range:

- `traefik 3.7.13`

## Package advisory (CVE-2026-88009)

Affected packages:

- `github.com/traefik/traefik/v3 >= 3.0.0, < 3.7.13`
- `github.com/traefik/traefik/v2 < 2.11.57`

Patched in:

- `github.com/traefik/traefik/v3 3.7.13`
- `github.com/traefik/traefik/v2 2.11.57`

Source: https://osv.dev/vulnerability/GHSA-f52w-8j3h-j724