SB2026070936 - Multiple vulnerabilities in Traefik

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Main Vulnerability Database SB2026070936

SB2026070936 - Multiple vulnerabilities in Traefik

Published: July 9, 2026

Security Bulletin ID SB2026070936
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Path traversal (CVE-ID: N/A)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass authentication and access protected routes.

The vulnerability exists due to path traversal in ReplacePathRegex middleware when processing a crafted HTTP request that produces an un-normalized replacement path. A remote attacker can send a specially crafted request to bypass authentication and access protected routes.

The issue occurs only when ReplacePathRegex is configured with a regular expression that captures user-controlled path segments without a mandatory separator, and exploitation depends on a backend that normalizes the forwarded path.


2) Incorrect authorization (CVE-ID: N/A)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to inject attacker-selected authenticated identity headers into downstream applications.

The vulnerability exists due to incorrect authorization in HTTPRoute backendRef ExtensionRef resolution in Traefik's Kubernetes Gateway API provider when resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef for a cross-namespace backend Service. A remote user can create a crafted HTTPRoute that binds a Middleware from the backend namespace without a separate grant to inject attacker-selected authenticated identity headers into downstream applications.

Exploitation requires HTTPRoute authoring capability and a ReferenceGrant that permits a cross-namespace Service reference.


3) Incorrect authorization (CVE-ID: N/A)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to cause Traefik to use unauthorized cross-provider backend transport settings.

The vulnerability exists due to improper access control in the Kubernetes CRD provider IngressRouteTCP service serversTransport reference handling when processing cross-provider serversTransport references. A remote user can set a crafted serversTransport reference such as foo@file to cause Traefik to use unauthorized cross-provider backend transport settings.

This can cause Traefik to apply operator-defined backend mTLS client certificates, SPIFFE identity, or PROXY protocol settings from a file-provider TCPServersTransport that the namespace should not be allowed to reference.


Remediation

Install update from vendor's website.

References