fusermount in fuse 2.8.5 and earlier does not perform a chdir to / before performing a mount or umount, which allows local users to unmount arbitrary directories via unspecified vectors.

fuse 2.8.5 and earlier does not properly handle when /etc/mtab cannot be updated, which allows local users to unmount arbitrary directories via a symlink attack.

Certain legacy functionality in fusermount in fuse 2.8.5 and earlier, when util-linux does not support the --no-canonicalize option, allows local users to bypass intended access restrictions and unmount arbitrary directories via a symlink attack.