Pidgin is an instant messaging program which can log in to multiple accounts on multiple instant messaging networks simultaneously. An invalid pointer dereference bug was found in the way the Pidgin OSCAR protocol implementation processed lists of contacts. A remote attacker could send a specially-crafted contact list to a user running Pidgin, causing Pidgin to crash. A NULL pointer dereference flaw was found in the way the Pidgin IRC protocol plug-in handles IRC topics. A malicious IRC server could send a specially-crafted IRC TOPIC message, which once received by Pidgin, would lead to a denial of service . A NULL pointer dereference flaw was found in the way the Pidgin MSN protocol plug-in handles improper MSNSLP invitations. A remote attacker could send a specially-crafted MSNSLP invitation request, which once accepted by a valid Pidgin user, would lead to a denial of service . All Pidgin users should upgrade to this updated package, which contains backported patches to resolve these issues. Pidgin must be restarted for this update to take effect.