As part of their Incremental Service Modelling, Microsoft have released SQL Server 2012 Service Pack 1 Cumulative Update #12.
To apply this cumulative update package, you must be running SQL Server 2012 SP1. So it is pertinent for versions 11.0.3000 — 11.0.3449.0 but is not for SQL Server 2012 RTM (11.0.2100 — 11.0.2999).
The build number of the cumulative update package is 11.0.3470.0 . You may have to restart the computer after you apply this cumulative update package.
This CU contains 22 fixes, the highlights for me being:
2975743 FIX: Incorrect result and exception occur when you use MDX query to do session cube grouping in SSAS
2989512 FIX: MDX query returns no result when the cache is not cleared after you run a previous query in OLAP or tabular model