---
id: CVE-2026-85595
title: >-
  Traefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain
  an authentication bypass vulnerability in the digestAuth middleware where
  unknown usernames receive an empty secret instead of rejection
summary: >-
  Traefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain
  an authentication bypass vulnerability in the digestAuth middleware where
  unknown usernames receive an empty secret instead of rejection. Attackers can
  compute …
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-287
  - CWE-305
vendor: traefik
product: traefik
affected:
  - traefik < 2.11.55
  - 'traefik >= 3.0.0, < 3.7.11'
patched:
  - traefik 3.7.11
published: '2026-09-04'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T20:42:43.003'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85595'
references:
  - url: 'https://github.com/traefik/traefik/security/advisories/GHSA-5w68-77r2-r64c'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/traefik-before-2.11.55-authentication-bypass-via-digestauth
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-85595.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-85595'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2529027'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-85595'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85595'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00445
epssPercentile: 0.37968
scores:
  nvd: 9.8
  vendor: 9.1
ingestedAt: '2026-09-05T22:45:53.787Z'
---

## Overview

Traefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain an authentication bypass vulnerability in the digestAuth middleware where unknown usernames receive an empty secret instead of rejection. Attackers can compute a valid digest response using the empty secret and arbitrary credentials to bypass authentication on any digestAuth-protected route without a valid username or password.

## Affected

- `traefik < 2.11.55`
- `traefik >= 3.0.0, < 3.7.11`

## Remediation

Upgrade past the affected range:

- `traefik 3.7.11`

## Vendor advisories

- **Red Hat VEX** · Critical · affected: Red Hat OpenShift Dev Spaces · no fix planned: Red Hat OpenShift Dev Spaces · updated 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-85595.json)