Traefik before v2.11.55 contains a TLS option conflict resolution vulnerability that allows unauthenticated attackers to bypass client-certificate authentication by creating conflicting TLS options on multi-host routers. Attackers can reach protected backends by exploiting shared TLS resolution across multiple hostnames in a single router rule, causing the strict mTLS requirement to fall back to default options for all hosts.

Project Subscriptions

Vendors Products
Traefik Subscribe
Traefik Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 04 Sep 2026 11:45:00 +0000

Type Values Removed Values Added
Description Traefik before v2.11.55 contains a TLS option conflict resolution vulnerability that allows unauthenticated attackers to bypass client-certificate authentication by creating conflicting TLS options on multi-host routers. Attackers can reach protected backends by exploiting shared TLS resolution across multiple hostnames in a single router rule, causing the strict mTLS requirement to fall back to default options for all hosts.
Title Traefik before v2.11.55 mTLS Bypass via TLS Option Conflict
First Time appeared Traefik
Traefik traefik
Weaknesses CWE-863
CPEs cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
Vendors & Products Traefik
Traefik traefik
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-04T11:30:00.783Z

Reserved: 2026-09-04T11:00:28.730Z

Link: CVE-2026-85597

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-04T12:17:23.210

Modified: 2026-09-04T12:17:23.210

Link: CVE-2026-85597

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-04T13:00:05Z

Weaknesses