`EnableEscapeCommandline` only controls the <Enter>~C commandline. The reason that is disabled in current OpenSSH by default is OpenBSD `pledge` support: http

`EnableEscapeCommandline` only controls the <Enter>~C commandline. The reason that is disabled in current OpenSSH by default is OpenBSD `pledge` support: https://security.stackexchange.com/questions/280793/what-attack-vectors-are-enabled-on-ssh-with-the-usage-of-enableescapecommandline https://security.stackexchange.com/questions/280793/what-att... On my Linux, cat<Enter>~. closes the connection as expected, and no ~ is shown in the terminal.