---
id: CVE-2026-65600
title: >-
  Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6
  contain an authentication bypass via path traversal in the ReplacePathRegex
  middleware
summary: >-
  Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6
  contain an authentication bypass via path traversal in the ReplacePathRegex
  middleware. When ReplacePathRegex is configured with a regex that captures
  user-contr…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-22
vendor: traefik
product: traefik
affected:
  - traefik < 2.11.52
  - 'traefik >= 3.6.0, < 3.6.23'
  - 'traefik >= 3.7.0, < 3.7.7'
patched:
  - traefik 3.7.7
published: '2026-07-22'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T16:17:28.820'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-65600'
references:
  - url: 'https://github.com/traefik/traefik/security/advisories/GHSA-cxjq-mrr5-89rv'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/traefik-before-authentication-bypass-via-replacepathregex
    label: disclosure@vulncheck.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-65600'
  - url: >-
      https://github.com/traefik/traefik/commit/3f10dd442479530560f010167cac2947676d9b29
  - url: 'https://github.com/traefik/traefik/releases/tag/v2.11.52'
  - url: 'https://github.com/traefik/traefik/releases/tag/v3.6.23'
  - url: 'https://github.com/traefik/traefik/releases/tag/v3.7.7'
  - url: 'https://github.com/advisories/GHSA-cxjq-mrr5-89rv'
tags:
  - nvd
  - cve.org
  - ghsa
  - go
  - score-dispute
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-07-23T19:08:10.643487Z'
scores:
  nvd: 5.3
  cna: 7.8
  ghsa: 9.1
epss: 0.00621
epssPercentile: 0.49569
aliases:
  - GHSA-cxjq-mrr5-89rv
ecosystem: go
ingestedAt: '2026-08-06T17:00:12.691Z'
---

## Overview

Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6 contain an authentication bypass via path traversal in the ReplacePathRegex middleware. When ReplacePathRegex is configured with a regex that captures user-controlled path segments without a mandatory path separator (e.g. regex "^/api(.*)", replacement "/$1"), the middleware forwards the replaced path to the backend without validating that it matches its normalized form. An unauthenticated remote attacker can send a crafted request (e.g. GET /api../admin) that produces an un-normalized path such as /../admin, which a backend that normalizes paths resolves to a protected route, bypassing authentication middleware. Fixed in v2.11.52, v3.6.23, and v3.7.7.

## Affected

- `traefik < 2.11.52`
- `traefik >= 3.6.0, < 3.6.23`
- `traefik >= 3.7.0, < 3.7.7`

## Remediation

Upgrade past the affected range:

- `traefik 3.7.7`

## Package advisory (CVE-2026-65600)

Affected packages:

- `github.com/traefik/traefik/v2 <= 2.11.51`
- `github.com/traefik/traefik/v3 <= 3.6.22`
- `github.com/traefik/traefik/v3 >= 3.7.0, <= 3.7.6`
- `github.com/traefik/traefik <= 1.7.34`

Patched in:

- `github.com/traefik/traefik/v2 2.11.52`
- `github.com/traefik/traefik/v3 3.6.23`
- `github.com/traefik/traefik/v3 3.7.7`

Source: https://github.com/advisories/GHSA-cxjq-mrr5-89rv