At Aug-21 17:44:24UTC, they released PHP5.5.3.
Anyway, I downloaded a Thread Safe version php-5.5.3-Win32-VC11-x86.zip for my server (Windows7HP+SP1(x86)). It requires VC11. If you don’t have VC11 on your Windows, you must install vcredist_x__.exe before the PHP configuration.
As the official PHP binary includes php5apache2_4.dll, I extract the zip archive and replace all PHP5.5.2 files with all PHP5.5.3 files except my php.ini. Then, I restart my Apache. That’s it.
If you need how to configure PHP5.5, please see the post. It is for a mbstrings user, but the information gives some help for you.