Race condition in the safe_open function in the Mutt mail client 1.5.12 and earlier, when creating temporary files in an NFS filesystem, allows local users to overwrite arbitrary files due to limitations of the use of the O_EXCL flag on NFS filesystems.

The mutt_adv_mktemp function in the Mutt mail client 1.5.12 and earlier does not properly verify that temporary files have been created with restricted permissions, which might allow local users to create files with weak permissions via a race condition between the mktemp and safe_fopen function calls.

Stack-based buffer overflow in the browse_get_namespace function in imap/browse.c of Mutt 1.4.2.1 and earlier allows remote attackers to cause a denial of service (crash) or execute arbitrary code via long namespaces received from the IMAP server.