A flaw was found in util-linux's libmount. An issue related to parsing the /proc/self/mountinfo file allows an unprivileged user to unmount other users' filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory.

A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker in its string form. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.