On PHP.net site today, they've announced the latest releases in the PHP 5.3.x and 5.4.x series - PHP 5.3.19 and PHP 5.4.9:

The PHP development team announces the immediate availability of PHP 5.4.9 and PHP 5.3.19. These releases fix over 15 bugs. All users of PHP are encouraged to upgrade to PHP 5.4.9, or at least 5.3.19. For source downloads of PHP 5.4.9 and PHP 5.3.19 please visit our downloads page, Windows binaries can be found on windows.php.net/download/.

You can view a complete list of changes in this edition's Changelog (including references to both core and extension bugfixes).