High severity · published Sep 10, 2026
CVE-2026-88009
Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging
8.2
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TR
traefik · traefik
< 2.11.57; >= 3.0.0, < 3.7.13 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-88009
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-88009
Patch
https://github.com/traefik/traefik/commit/58d1e9ca204526823211e30fd4634101c59d58e9
Issue Tracking
https://github.com/traefik/traefik/pull/13796
Release Notes
https://github.com/traefik/traefik/releases/tag/v2.11.57
Release Notes
https://github.com/traefik/traefik/releases/tag/v3.7.13
Patch
https://github.com/traefik/traefik/security/advisories/GHSA-f52w-8j3h-j724
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