Como observado na% man_de% manpage, a opção mount
mount ativa implicitamente a opção user
user Allow an ordinary user to mount the filesystem. The name of the
mounting user is written to mtab so that he can unmount the
filesystem again. This option implies the options noexec,
nosuid, and nodev (unless overridden by subsequent options, as
in the option line user,exec,dev,suid).
onde
noexec Do not allow direct execution of any binaries on the mounted
filesystem.