Traefik up to 2.11.51/3.6.0-3.7.6 ReplacePathRegex middleware path traversal

Summaryinfo

A vulnerability marked as critical has been reported in Traefik up to 2.11.51/3.6.0-3.7.6. This issue affects some unknown processing of the component ReplacePathRegex middleware. This manipulation causes path traversal. The identification of this vulnerability is CVE-2026-65600. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Traefik up to 2.11.51/3.6.0-3.7.6. It has been declared as critical. Affected by this vulnerability is an unknown code of the component ReplacePathRegex middleware. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6 contain an authentication bypass via path traversal in the ReplacePathRegex middleware. When ReplacePathRegex is configured with a regex that captures user-controlled path segments without a mandatory path separator (e.g. regex "^/api(.*)", replacement "/$1"), the middleware forwards the replaced path to the backend without validating that it matches its normalized form. An unauthenticated remote attacker can send a crafted request (e.g. GET /api../admin) that produces an un-normalized path such as /../admin, which a backend that normalizes paths resolves to a protected route, bypassing authentication middleware. Fixed in v2.11.52, v3.6.23, and v3.7.7.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-65600 since 07/22/2026. 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. MITRE ATT&CK project uses the attack technique T1006 for this issue.

Upgrading to version 2.11.52, 3.6.23 or 3.7.7 eliminates this vulnerability.

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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
• 2.11.48
• 2.11.49
• 2.11.50
• 2.11.51
• 3.6.0-3.7.0
• 3.6.0-3.7.1
• 3.6.0-3.7.2
• 3.6.0-3.7.3
• 3.6.0-3.7.4
• 3.6.0-3.7.5
• 3.6.0-3.7.6

Website

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

CPE 2.3info

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CPE 2.2info

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