CVE-2026-48020

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.

CVSS v3 10.0 CRITICAL

10.0^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.8

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/traefik/traefik/releases/tag/v2.11.48	Patch Release Notes
https://github.com/traefik/traefik/releases/tag/v3.6.19	Patch Release Notes
https://github.com/traefik/traefik/releases/tag/v3.7.3	Patch Release Notes
https://github.com/traefik/traefik/security/advisories/GHSA-xf64-8mw2-4gr2	Exploit Mitigation Patch Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:62260
https://access.redhat.com/security/cve/CVE-2026-48020
https://bugzilla.redhat.com/show_bug.cgi?id=2491915
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48020.json

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:traefik:traefik::::::::
	cpe:2.3:a:traefik:traefik::::::::
	cpe:2.3:a:traefik:traefik::::::::

History

No history.

Information

Published : 2026-06-23 20:16

Updated : 2026-09-02 13:17

NVD link : CVE-2026-48020

Mitre link : CVE-2026-48020

CVE.ORG link : CVE-2026-48020

JSON object : View

Products Affected

traefik

traefik

CWE

CWE-288

Authentication Bypass Using an Alternate Path or Channel

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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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 \u2014 such as admin or internal configuration endpoints \u2014 without satisfying the authentication middleware attached to the protected router. 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