Pidgin is an instant messaging program which can log in to multiple accounts on multiple instant messaging networks simultaneously. An input sanitization flaw was found in the way the Pidgin SILC protocol plug-in escaped certain UTF-8 characters. A remote attacker could use this flaw to crash Pidgin via a specially-crafted SILC message. Multiple NULL pointer dereference flaws were found in the way the Pidgin Yahoo! Messenger Protocol plug-in handled malformed YMSG packets. A remote attacker could use these flaws to crash Pidgin via a specially-crafted notification message. Red Hat would like to thank the Pidgin project for reporting CVE-2011-1091. Upstream acknowledges Marius Wachtler as the original reporter of CVE-2011-1091. All Pidgin users should upgrade to these updated packages, which contain backported patches to resolve these issues. Pidgin must be restarted for this update to take effect.