Traefik up to 2.11.47/3.6.18/3.7.2 authentication bypass

Summaryinfo

A vulnerability was found in Traefik up to 2.11.47/3.6.18/3.7.2. It has been declared as critical. This affects an unknown function. Executing a manipulation can lead to authentication bypass. This vulnerability is tracked as CVE-2026-48020. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Traefik up to 2.11.47/3.6.18/3.7.2. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a authentication bypass vulnerability. The CWE definition for the vulnerability is CWE-288. A product requires authentication, but the product has an alternate path or channel that does not require authentication. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-48020 since 05/20/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 2.11.48, 3.6.19 or 3.7.3 eliminates this vulnerability. The upgrade is hosted for download at github.com.

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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
• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4
• 3.6.5
• 3.6.6
• 3.6.7
• 3.6.8
• 3.6.9
• 3.6.10
• 3.6.11
• 3.6.12
• 3.6.13
• 3.6.14
• 3.6.15
• 3.6.16
• 3.6.17
• 3.6.18
• 3.7.0
• 3.7.1
• 3.7.2

Website

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

CPE 2.3info

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CPE 2.2info

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