The 4th cumulative update release for SQL Server 2012 SP1 is now available for download at the Microsoft Support site. Cumulative Update 4 contains all the SQL Server 2012 SP1 hotfixes which have been available since the initial release of SQL Server 2012 SP1.
To learn more about the release or servicing model, please visit:
Previous Cumulative Update KB Articles:
Admins of ReportingServices 2012 read this before installing CU4