In Wireshark 2.6.0 to 2.6.3, the CoAP dissector could crash. This was addressed in epan/dissectors/packet-coap.c by ensuring that the piv length is correctly computed.
https://www.wireshark.org/security/wnpa-sec-2018-49.html
https://www.debian.org/security/2018/dsa-4359
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=15172
http://www.securitytracker.com/id/1041909
http://www.securityfocus.com/bid/105583
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00027.html