The PHP.net site has an announcement about the release of the latest version on the PHP 5.6x series: PHP 5.6.15:

The PHP development team announces the immediate availability of PHP 5.6.15. Several bugs have been fixed. All PHP 5.6 users are encouraged to upgrade to this version.

Bugfixes in this update include changes in closure handling, DateTimeImmutable, mcrypt_encrypt and segfaults in the opcache handling (gc_remove_from_buffer). You can get this latest release from either the main downloads page (source) or from the windows.php.net site for the Windows binaries.