Version: 
2.6.19
Released Date: 
2008/02/11

 This release addresses a couple of bug fixes, and a bug with the regex_replace modifier that can allow php functions to be called in templates. If you use the security features of Smarty, you should upgrade immediately. As a quick fix, you can replace the modifier.regex_replace.php plugin with the new one.

ChangeLog here. download it here.