by Kastro
Paper/Archive/CVE-2026-114656

CVE-2026-114656

traefik traefik — Traefik before 2.11.58 and 3.7.13 mTLS Bypass via Negated Host Matcher

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
29
CVSS 9.3 (NVD)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 5.5.055 × 201.1No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
traefik< 2.11.582.11.58CNA
traefik3.0.0 – < 3.7.133.7.13CNA

Scores by source

NVD9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
VulnCheck (CNA)7.5CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N
VulnCheck (CNA)6.9CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N

References

advisorygithub.com/traefik/traefik/security/advisories/GHSA-2272-4vv8-65wwwriteupvulncheck.com/advisories/traefik-before-2.11.58-and-3.7.13-mtls-bypass-via-negated-host-matcher