The PHP development team has officially announced the release of the latest version of PHP in the 5.3.x series - PHP 5.3.10:

The PHP development team would like to announce the immediate availability of PHP 5.3.10. This release delivers a critical security fix. [...] Fixed arbitrary remote code execution vulnerability reported by Stefan Esser, CVE-2012-0830.

It is highly recommended that users upgrade to this latest version to avoid falling victim to this recently introduced bug relating to the new "max_input_vars" setting added to protect from the overflow issue recently brought up in the PHP community.