In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands in a mountpoint name, which is…

In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands in a mountpoint name, which is mishandled during a umount command (within Bash) by a different user, as demonstrated by logging in as root and entering umount followed by a tab character for autocompletion.