CVE-2026-88009

Medium

Elevated severity or exploit probability.

CVSS base

8.2 HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

EPSS — probability of exploitation (30 days)

0.3%

19.4th percentile

CISA KEV

Not listed

Weakness / dates

CWE-444

Published 2026-09-10 · modified 2026-09-14

CVSS breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	N	None
Scope	U	Unchanged
Confidentiality	H	High
Integrity	L	Low
Availability	N	None

Timeline

2026-09-10 — Published (NVD)
2026-09-14 — Last modified (NVD)

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.

Affected

traefik

References

Official: NVD · CVE.org