CVE-2026-72693 Kbd: local privilege escalation in openvt via incorrect process owner verification allowing passwordless root login

openvt -u is intended to identify the owner of the current VT and then execute login as that user from a privileged context. In the documented kbrequest/init usage, the ownership test in authenticateuser relies on stat"/proc//fd/0". stat on /proc//fd/0 follows the symlink to the underlying TTY...