CVE-2026-45389

High severity, CVSS 7.4. EPSS: 0.2% chance of exploitation in the next 30 days.

In OCaml-TLS before 2.1.0, the server implementation does insufficient checks of the certificate provided by the client (when doing client authentication), which allows impersonation with certificates that are not meant for client authentication (because of KeyUsage and ExtendedKeyUsage).

Published 2026-06-15. Last modified 2026-06-17.