SeaMonkey is an open source Web browser, email and newsgroup client, IRC chat client, and HTML editor. Several flaws were found in the processing of malformed web content. A web page containing malicious content could cause SeaMonkey to crash or, potentially, execute arbitrary code as the user running SeaMonkey. A flaw was found in the way malformed content was processed. A website containing specially-crafted content could, potentially, trick a SeaMonkey user into uploading a local file. A flaw was found in the way SeaMonkey treated HTTPOnly cookies. An attacker able to execute arbitrary JavaScript on a target site using HTTPOnly cookies may be able to use this flaw to steal the cookie. All SeaMonkey users should upgrade to these updated packages, which contain backported patches that correct these issues. After installing the update, SeaMonkey must be restarted for the changes to take effect.