SeaMonkey is an open source web browser, email and newsgroup client, IRC chat client, and HTML editor. A flaw was found in the way SeaMonkey handled malformed JPEG images. A website containing a malicious JPEG image could cause SeaMonkey to crash or, potentially, execute arbitrary code with the privileges of the user running SeaMonkey. Multiple dangling pointer flaws were found in SeaMonkey. A web page containing malicious content could cause SeaMonkey to crash or, potentially, execute arbitrary code with the privileges of the user running SeaMonkey. 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 with the privileges of the user running SeaMonkey. An integer overflow flaw was found in the way SeaMonkey handled JavaScript Array objects. A website containing malicious JavaScript could cause SeaMonkey to execute that JavaScript with the privileges of the user running SeaMonkey. A use-after-free flaw was found in the way SeaMonkey handled malformed JavaScript. A website containing malicious JavaScript could cause SeaMonkey to execute that JavaScript with the privileges of the user running SeaMonkey. It was found that SeaMonkey could treat two separate cookies as interchangeable if both were for the same domain name but one of those domain names had a trailing "." character. This violates the same-origin policy and could possibly lead to data being leaked to the wrong domain. All SeaMonkey users should upgrade to these updated packages, which correct these issues. After installing the update, SeaMonkey must be restarted for the changes to take effect.