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.
https://www.debian.org/security/2018/dsa-4277
https://usn.ubuntu.com/3719-3/
https://security.gentoo.org/glsa/201810-07
https://neomutt.org/2018/07/16/release
https://lists.debian.org/debian-lts-announce/2018/08/msg00001.html
https://gitlab.com/muttmua/mutt/commit/9347b5c01dc52682cb6be11539d9b7ebceae4416
https://github.com/neomutt/neomutt/commit/36a29280448097f34ce9c94606195f2ac643fed1