Buffer overflow in copy.c in Mutt before 1.5.23 allows remote attackers to cause a denial of service (crash) via a crafted RFC2047 header line, related to address expansion.

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.

Buffer overflow in Mutt 1.4.0 and possibly earlier versions, 1.5.x up to 1.5.3, and other programs that use Mutt code such as Balsa before 2.0.10, allows a remote malicious IMAP server to cause a denial of service (crash) and possibly execute arbitrary code via a crafted folder.