CVE-2026-48020

High

High exploit probability or critical severity with a known exploit.

CVSS base

10.0 CRITICAL

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

EPSS — probability of exploitation (30 days)

0.8%

53.8th percentile

CISA KEV

Not listed

Weakness / dates

CWE-22

Published 2026-06-23 · modified 2026-09-02

CVSS breakdown

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

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

Timeline

2026-06-23 — Published (NVD)
2026-09-02 — Last modified (NVD)

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

Affected

traefik

References

Official: NVD · CVE.org