CVE-2026-53622
Published: 23 June 2026
Summary
CVE-2026-53622 is a high-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Traefik Traefik. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 15.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-38576
Vulnerability details
Traefik is an HTTP reverse proxy and load balancer. Prior to 3.7.3, there is 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,…
more
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 3.7.3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct authentication bypass on public-facing reverse proxy via alternate TLS path (CWE-288).
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.
Users can identify logons via alternate paths or channels by reviewing the previous logon time.
Adaptive requirements can apply across access paths, reducing the ability to bypass authentication via alternate channels or paths.
Centralized IdPs close alternate authentication paths that enable bypass.
Enforces authentication for non-organizational users, making it harder to bypass via alternate paths or channels.
Requires authentication to occur exclusively over the isolated trusted path, directly preventing bypass via alternate or untrusted channels.