fusermount in FUSE before 2.4.1, if installed setuid root, allows local users to corrupt /etc/mtab and possibly modify mount options by performing a mount over a directory whose name contains certain special characters.

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.