PHP.net ended support for PHP 5.2 on 6 January 2011 and for PHP 5.3 on 14 August 2014. While Acquia has been working to maintain support for these deprecated versions of PHP, support for these versions will end, in favor of PHP 5.5 and 5.6, on Tuesday, 1 September 2015. At that time, we will remove these obsolete and unsupported versions of PHP and convert all remaining environments to PHP 5.6. This deadline will not be extended, as it is critical your website be upgraded to ensure its continued security.
PHP 5.5 and 5.6 provide extensive improvements in performance and security over previous versions. While PHP 5.5 is available, we strongly recommend customers move to PHP 5.6 immediately (after appropriate testing) because php.net will end active support for PHP 5.5 in June 2015. Backwards incompatibility between PHP 5.6 and PHP 5.5 is minimal and consists of bug fixes and security improvements.
Is there any action required on my part?
All environments for all applications must be upgraded to PHP 5.5 or PHP 5.6 before Tuesday, 1 September 2015. Prior to that date, you should upgrade your non-production sites in order to test for any incompatibilities in your website. We recommend beginning with your non-production upgrades as soon as possible to ensure you have time to test, prior to upgrading your production site. Once you have resolved any incompatibilities, upgrade your production website before the end-of-life deadline. See Configuring PHP settings for instructions on changing your PHP version.