As is mentioned in this post on the PHP.net site, the latest version in the PH 5.6.x series has been released: PHP 5.6.25.

The PHP development team announces the immediate availability of PHP 5.6.25. This is a security release. Several security bugs were fixed in this release. All PHP 5.6 users are encouraged to upgrade to this version.

Fixes in this release includes changes to Core, Calendar, Curl, DOM and GD functionality (including a few security-related issues). You can get this latest release from the main downloads page or windows.php.net for the Windows binaries. For a full list of changes and related bugs, check out the full Changelog.