The IRC protocol plugin in libpurple in Pidgin before 2.10.8 does not validate argument counts, which allows remote IRC servers to cause a denial of service (application crash) via a crafted message.
hg.pidgin.im/pidgin/main/rev/4d9be297d399
hg.pidgin.im/pidgin/main/rev/5845d9fa7084
hg.pidgin.im/pidgin/main/rev/6b0e0566af20
hg.pidgin.im/pidgin/main/rev/7d0fb0c6d8d4
hg.pidgin.im/pidgin/main/rev/9f132a6855cd
hg.pidgin.im/pidgin/main/rev/a167504359e5
lists.opensuse.org/opensuse-updates/2014-02/msg00039.html
lists.opensuse.org/opensuse-updates/2014-03/msg00005.html
pidgin.im/news/security/?id=85
www.debian.org/security/2014/dsa-2859
www.ubuntu.com/usn/USN-2100-1
rhn.redhat.com/errata/RHSA-2014-0139.html