Description
Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.57, and 3.7.13, Traefik accepts a rootless HTTP/1 request target that Go stores in URL.Opaque while leaving URL.Path empty. The rewriteRequestBuilder path evaluates routing, path sanitization, forwardAuth, encodedCharacters, and access logging against a path normalized to / but forwards URL.Opaque verbatim to the backend, allowing cross-vhost routing bypass, path-scoped authorization bypass, and access-log evasion when the backend interprets the opaque target as a path. This issue is fixed in 2.11.57 and 3.7.13.
Published: 2026-09-10
Score: 8.8 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Thu, 10 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Description Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.57, and 3.7.13, Traefik accepts a rootless HTTP/1 request target that Go stores in URL.Opaque while leaving URL.Path empty. The rewriteRequestBuilder path evaluates routing, path sanitization, forwardAuth, encodedCharacters, and access logging against a path normalized to / but forwards URL.Opaque verbatim to the backend, allowing cross-vhost routing bypass, path-scoped authorization bypass, and access-log evasion when the backend interprets the opaque target as a path. This issue is fixed in 2.11.57 and 3.7.13.
Title Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging
Weaknesses CWE-1286
CWE-444
References
Metrics cvssV4_0

{'score': 8.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-10T15:40:16.096Z

Reserved: 2026-09-09T19:19:27.406Z

Link: CVE-2026-88009

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-1286

    Improper Validation of Syntactic Correctness of Input

  • CWE-444

    Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')