On the PHP.net site they've announced the latest releases of the language - PHP 5.4.7 and 5.3.17:

The PHP development team announces the immediate availability of PHP 5.4.7 and PHP 5.3.17. These releases fix over 20 bugs. All users of PHP are encouraged to upgrade to PHP 5.4.7, or at least 5.3.17. Key enhancements in these releases include bugs #62955 and #62460.

If you'd like to see the full list of changes you can see them in the Changelog. To download this latest release you can head over here: source downloads, Windows downloads.