Traefik up to 2.11.54 digestAuth middleware improper authentication

Summaryinfo

A vulnerability classified as critical has been found in Traefik up to 2.11.54. Affected by this vulnerability is an unknown functionality of the component digestAuth middleware. This manipulation causes improper authentication. This vulnerability is handled as CVE-2026-85595. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Traefik up to 2.11.54. It has been declared as critical. Affected by this vulnerability is some unknown processing of the component digestAuth middleware. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Traefik versions before v2.11.55 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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-85595 since 09/04/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

Upgrading to version 2.11.55 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Traefik

Version

• 2.11.0
• 2.11.1
• 2.11.2
• 2.11.3
• 2.11.4
• 2.11.5
• 2.11.6
• 2.11.7
• 2.11.8
• 2.11.9
• 2.11.10
• 2.11.11
• 2.11.12
• 2.11.13
• 2.11.14
• 2.11.15
• 2.11.16
• 2.11.17
• 2.11.18
• 2.11.19
• 2.11.20
• 2.11.21
• 2.11.22
• 2.11.23
• 2.11.24
• 2.11.25
• 2.11.26
• 2.11.27
• 2.11.28
• 2.11.29
• 2.11.30
• 2.11.31
• 2.11.32
• 2.11.33
• 2.11.34
• 2.11.35
• 2.11.36
• 2.11.37
• 2.11.38
• 2.11.39
• 2.11.40
• 2.11.41
• 2.11.42
• 2.11.43
• 2.11.44
• 2.11.45
• 2.11.46
• 2.11.47
• 2.11.48
• 2.11.49
• 2.11.50
• 2.11.51
• 2.11.52
• 2.11.53
• 2.11.54

Website

• Product: https://github.com/traefik/traefik/

CPE 2.3info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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