CVE-2026-85597

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.

Scoring

Severity
HIGH
CVSS base score
8.2
CVSS 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
EPSS probability
0.23%
CWE
CWE-863
Published
2026-09-04
Last modified
2026-09-05

Affected products

Weakness type

Related vulnerabilities

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