CVE-2026-85595GHSA-5w68-77r2-r64c

Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth

traefik traefik

CVSS

9.3Critical

ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV

Exploit odds (EPSS)0.69%Chance of exploitation activity in the next 30 days, higher than 52% of CVEs. Scored 24 Oct 2026FIRST EPSS

Fixed in2.11.55Fixed versionCVE List

Published4 Sep 2026Updated 8 Oct 2026CVE List

What fixes it

2.11.55traefikCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

4 Sep 2026, 11:29 UTCPublishedCVE List
25 Oct 2026, 00:01 UTCExploit code publicGitHub proof-of-concept repositories

Reports 1

1 outlet mention it. Reports are not confirmation; each links to its source.

Boreas37/CVE-2026-85595-PoC: CVE-2026-85595 — Traefik digestAuth authentication bypass (unknown username => empty HA1). Lab-verified: v3.7.10 bypass, v3.7.11 401.GitHub proof-of-concept repositories, 25 Oct 2026Exploit code

Description

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.

Text from CVE List

Affected versions 3

traefikaffected: all versions before 2.11.55CVE List
traefikunaffected: 2.11.55CVE List
traefikaffected: 3.0.0 through 3.7.10CVE List