Failover Cluster - Recommended hotfixes and updates for Windows Server 2012 RTM and R2 based clusters

Checkout KB2920151 for getting a comprehensive list of the recommended hotfixes and updates for clusters based on Windows Server 2012 R2

https://support.microsoft.com/kb/2920151/en-us

+ Checkout Rollup Update June which includes several Hyper-V and Cluster relevant patches too.

https://support.microsoft.com/kb/2962409/en-us

Same exists for Windows 2012 RTM based clusters too

https://support.microsoft.com/kb/2784261/en-us

Also take a look at the Cluster-Aware Updating feature which is introduced in 2012 R2 –> Cluster-Aware Updating Overview 

….Stay tuned ;)