{"cve":"CVE-2026-53622","nvd":{"published":"2026-06-23T20:16:48.777","modified":"2026-09-02T13:18:02.010","status":"Modified","description":"Traefik is an HTTP reverse proxy and load balancer. Versions prior to 3.7.3, 3.6.18, and 2.11.51 have a critical vulnerability in Traefik's HTTP/3 (QUIC) TLS configuration selection that allows unauthenticated clients to bypass router-specific mTLS enforcement. When HTTP/3 is enabled on an entrypoint, the TLS handshake selects the applicable TLS configuration through an exact, case-sensitive lookup on the SNI value, which fails to match wildcard host patterns (e.g., *.example.com) or case variants of the configured hostname. Because the handshake falls back to the default TLS configuration — which may not require client certificates — a client can complete the QUIC handshake without presenting a certificate, while the subsequent HTTP routing layer still dispatches the request to a backend protected by a router-specific mTLS policy. The issue affects deployments where HTTP/3 is enabled, a router uses a wildcard Host rule or case-insensitive hostname matching, a router-specific TLSOptions enforces client certificate authentication, and UDP access to the entrypoint is reachable by an attacker. This vulnerability is fixed in versions 3.7.3, 3.6.18, and 2.11.51.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":7.8},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N","score":10.0},"cwes":["CWE-288","CWE-289"],"references":["https://access.redhat.com/security/cve/CVE-2026-53622","https://bugzilla.redhat.com/show_bug.cgi?id=2491924","https://community.traefik.io/t/new-security-update-for-traefik-2-11-2-11-48-3-6-3-6-19-and-3-7-3-7-3/29917","https://github.com/traefik/traefik/compare/v3.6.17...v3.6.18","https://github.com/traefik/traefik/pull/13214"],"products":["traefik:traefik"],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-53622","score":0.00629,"percentile":0.50145,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-9cr8-q42q-g8m7","url":"https://osv.dev/vulnerability/GHSA-9cr8-q42q-g8m7","summary":"Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts","modified":"2026-09-10T03:50:49.229969907Z","packages":[{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","purl":"pkg:golang/github.com/traefik/traefik/v3","ranges":[">=3.7.0 <3.7.3"],"fixed":["3.7.3"]},{"ecosystem":"Go","name":"github.com/traefik/traefik/v2","purl":"pkg:golang/github.com/traefik/traefik/v2","ranges":["<2.11.51"],"fixed":["2.11.51"]},{"ecosystem":"Go","name":"github.com/traefik/traefik","purl":"pkg:golang/github.com/traefik/traefik","ranges":["<=1.7.34"],"fixed":[]},{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","purl":"pkg:golang/github.com/traefik/traefik/v3","ranges":["<3.6.18"],"fixed":["3.6.18"]}]},{"id":"GO-2026-5287","url":"https://osv.dev/vulnerability/GO-2026-5287","summary":"Traefik: HTTP/3 mTLS bypass via exact SNI TLSOptions lookup for wildcard and mixed-case hosts in github.com/traefik/traefik","modified":"2026-08-13T03:41:53.812568434Z","packages":[{"ecosystem":"Go","name":"github.com/traefik/traefik","purl":"pkg:golang/github.com/traefik/traefik","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/traefik/traefik/v2","purl":"pkg:golang/github.com/traefik/traefik/v2","ranges":["<2.11.51"],"fixed":["2.11.51"]},{"ecosystem":"Go","name":"github.com/traefik/traefik/v3","purl":"pkg:golang/github.com/traefik/traefik/v3","ranges":["<3.7.3"],"fixed":["3.7.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}