Konversation 1.4.x, 1.5.x, 1.6.x, and 1.7.x before 1.7.3 allow remote attackers to cause a denial of service (crash) via vectors related to parsing of IRC color formatting codes.
https://www.debian.org/security/2017/dsa-4033
https://lists.debian.org/debian-lts-announce/2017/11/msg00020.html
https://cgit.kde.org/konversation.git/commit/?h=1.7&id=6a7f59ee1b9dbc6e5cf9e5f3b306504d02b73ef0