SeaMonkey is an open source web browser, e-mail and newsgroup client, IRC chat client, and HTML editor. A heap-based buffer overflow flaw was found in the way SeaMonkey handled PNG images. A web page containing a malicious PNG image could cause SeaMonkey to crash or, possibly, execute arbitrary code with the privileges of the user running SeaMonkey. All SeaMonkey users should upgrade to these updated packages, which correct this issue. After installing the update, SeaMonkey must be restarted for the changes to take effect.