6.9 Medium

CVE-2026-114656 Traefik before 2.11.58 and 3.7.13 mTLS Bypass via Negated Host Matcher

Description

Traefik before 2.11.58 and 3.7.13 contains an authentication bypass vulnerability that allows unauthenticated clients to skip client-certificate checks because negated Host matchers are counted as served domains. Attackers can reach backends protected by RequireAndVerifyClientCert when a router rule with !Host() creates a TLS options conflict that falls back to the default options.

CVSS 4.0 detail

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N

Exploitable remotely over the network, without an account and without any user action; with no direct impact on the vulnerable system.

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: None
Interaction: None
Confidentiality: None
Integrity: None
Availability: None
Confidentiality of other systems: High
Integrity of other systems: Low
Availability of other systems: None

Affected products and versions

Product	Affected versions	Fixed in
traefik 3.7	earliest → < 3.7.13	3.7.13
traefik 3.0	3.0.0 → < 3.7.13	3.7.13

References

GitHub Security Advisory (GHSA-2272-4vv8-65ww) github.com
VulnCheck Advisory: Traefik before 2.11.58 and 3.7.13 mTLS Bypass via Negated Host Matcher www.vulncheck.com

Timeline

Published October 22, 2026
Last modified November 4, 2026

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