Stack-based buffer overflow in fish.cpp in the Fish plugin for ZNC, as used in ZNC for Windows (znc-msvc) 0.206 and earlier, allows remote attackers to cause a denial of service (crash) via a long string in a DH1080_INIT message.

znc.cpp in ZNC before 0.092 allows remote authenticated users to cause a denial of service (crash) by requesting traffic statistics when there is an active unauthenticated connection, which triggers a NULL pointer dereference, as demonstrated using (1) a traffic link in the web administration pages or (2) the traffic command in the /znc shell.