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_ssl.c in mutt 1.5.16 and other versions before 1.5.19, when OpenSSL is used, does not verify the domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

mutt_ssl.c in mutt 1.5.19 and 1.5.20, when OpenSSL is used, does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

Mutt 1.5.19, when linked against (1) OpenSSL (mutt_ssl.c) or (2) GnuTLS (mutt_ssl_gnutls.c), allows connections when only one TLS certificate in the chain is accepted instead of verifying the entire chain, which allows remote attackers to spoof trusted servers via a man-in-the-middle attack.

Buffer overflow in Mutt 1.4.2 might allow local users to execute arbitrary code via "&" characters in the GECOS field, which triggers the overflow during alias expansion.

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.

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.

Buffer overflow in the mutt_decode_xbit function in Handler.c for Mutt 1.5.10 allows remote attackers to execute arbitrary code, possibly due to interactions with libiconv or gettext.