fusermount in FUSE before 2.7.5, and 2.8.x before 2.8.2, allows local users to unmount an arbitrary FUSE filesystem share via a symlink attack on a mountpoint.
FUSE 2.x before 2.3.0 does not properly clear previously used memory from unfilled pages when the filesystem returns a short byte count to a read request, which may allow local users to obtain sensitive information.