Mozilla pushed out an update to its e-mail client Thunderbird today. The 18.104.22.168 update, for both Windows and Mac versions, corrects two potential exploits. Centered around Newsgroup functionality and an obscure UTF-8 hyperlink spoof, they could've allowed an attacker to execute arbitrary code.
A spate of bug fixes, memory leaks, and other less severe tweaks were addressed, too. The full changelog can be read here.