php 5.3, 5.4, 5.5 and 5.6 have also been updated to the latest builds (in the case of 5.3, 5.4 and 5.5 they are the final builds).
You may want to consider weaning off the 5.x versions of php, as 5.3, 5.4 and 5.5 are past their end of life. php. 5.6 will still be viable for a couple more years, so if you’re using an earlier version, take a look at moving to 5.6, or better yet, php 7.
To change the php version for your site, go to the IIS Tools section of Control Panel, and look for the dropdowns on the “ASP.NET/PHP Version” tab.