As part of their Incremental Service Modelling, Microsoft have released SQL Server 2014 Cumulative Update #4 for SQL Server 2014 SP1.
To apply this cumulative update package, you must be running SQL Server 2014 SP1. So it is pertinent for versions 2014.120.4100.1 - 2014.120.4427.24. Note you cannot apply this patch if you do not have SP1 installed.
The build number of the cumulative update package is 12.0.4436.0. You may have to restart the computer after you apply this cumulative update package. The cumulative update package updates only those components currently installed.
This update contains 34 updates. As usual, make sure you deploy Cumulative Updates in test environments before deploying straight to production and that you apply the most recent build that you apply the most recent build.
This Cumulative Update contains a change that Aaron Bertrand wrote about here, and a very bad idea it is to have changed @@VERSION. You need to review options 2 and 4 of this guide to determine SQL Server version.
This change is also in the latest Cumulative Update (11) for the RTM branch of SQL Server 2014. It's worth noting that two COD releases post-CU3 are not included in this update. The full info can be read on the SQL Sentry site, which covers the updates for both SP1 and RTM releases in SQL Server than I do in my bulletins.