An issue was discovered in Mutt before 1.10.1 and NeoMutt before 2018-07-16. imap/command.c mishandles a NO response without a message.

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.

Mutt does not verify that the smtps server hostname matches the domain name of the subject of an X.509 certificate, which allows man-in-the-middle attackers to spoof an SSL SMTP server via an arbitrary certificate, a different vulnerability than CVE-2009-3766.

Mutt 1.5.13 and earlier does not properly use the --status-fd argument when invoking GnuPG, which prevents Mutt from visually distinguishing between signed and unsigned portions of OpenPGP messages with multiple components, which allows remote attackers to forge the contents of a message without detection.

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.