CVE-2026-85595

Critical

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.

SeverityCritical

CVSS9.8

Exploit probability—

Product

Traefik

PublishedSep 4, 2026

First seenSep 4, 2026

Weakness typeCWE-287Improper authentication

How to fix

Update

traefik traefik2.11.55, 3.7.11 or later

Vendor advisories

github.com/traefik/traefik/security/advisories/GHSA-5w68-77r2-r64c

Affected products

Product	Affected versions	Fixed in
traefik traefik	v < 2.11.55, 3.0.0 ≤ v < 3.7.11	2.11.55, 3.7.11

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