In Wireshark 2.2.0 to 2.2.5 and 2.0.0 to 2.0.11, the IMAP dissector could crash, triggered by packet injection or a malformed capture file. This was addressed in epan/dissectors/packet-imap.c by calculating a line's end correctly.
https://www.wireshark.org/security/wnpa-sec-2017-12.html
https://security.gentoo.org/glsa/201706-12
https://lists.debian.org/debian-lts-announce/2019/01/msg00010.html
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=13466