The Office 2013 September 2014 Cumulative Updates are now available, please see the links below:
Project Server 2013 September 2014 Server Roll up package:
Project Server 2013 September 2014 CU:
Project 2013 September 2014 CU:
Also worth noting, if you haven’t done so already, install the March 2013 Public update: http://support.microsoft.com/kb/2768001 or Service Pack 1: http://support.microsoft.com/kb/2880553 if installing the September 2014 CU.
As always, test these updates on a replica test environment before deploying to production.