OpenSSH before 10.3 omits connection multiplexing confirmation for proxy-mode multiplexing sessions.Referenceshttps://www.openssh.org/releasenotes.html#10.3p1https://marc.info/?l=openssh-unix-dev&m=177513443901484&w=2https://www.openwall.com/lists/oss-security/2026/04/02/3
