Mutt before 1.14.3 allows an IMAP fcc/postpone man-in-the-middle attack via a PREAUTH response.
https://www.debian.org/security/2020/dsa-4708
https://www.debian.org/security/2020/dsa-4707
https://usn.ubuntu.com/4401-1/
https://security.gentoo.org/glsa/202007-57
https://lists.debian.org/debian-lts-announce/2020/06/msg00040.html
https://lists.debian.org/debian-lts-announce/2020/06/msg00039.html
https://github.com/muttmua/mutt/commit/3e88866dc60b5fa6aaba6fd7c1710c12c1c3cd01
https://bugs.gentoo.org/728300
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00070.html
http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00064.html