Exchange 2013 CU7, Exchange 2010 SP3 UR8, and Exchange 2007 SP3 UR15 were released a little while ago.
Exchange 2013 CU7 includes a security patch pulled from last month's updates. A separate patch is also available for CU6 and CU4 (CU4 because it is SP1). There is also another issue briefly mentioned about Exchange 2013 CU7 in the Exchange Team blog regarding backups. Because of that issue, I recommend you schedule your update to CU7 as soon as possible. http://blogs.technet.com/b/exchange/archive/2014/12/09/exchange-releases-december-2014.aspx
