Microsoft released the quarterly servicing update to Exchange Server 2013 – CU10 and updated UM Language Packs.
The release includes fixes for customer reported issues, minor product enhancements and previously released security bulletins. A complete list of customer reported issues resolved can be found in Knowledge Base Article KB3078678.
Cumulative Update 10 is the minimum version of Exchange Server 2013 which will co-exist with Exchange Server 2016.
You can read the full blog post at the Exchange Team Blog.