Exchange 2013 CU10 was released September 15th. Cumulative Update 10 or higher is required to co-exist with Exchange 2016. CU10 does not require a schema update unless you were running a version of Exchange 2013 older than CU7.
Warning: CU10 contains an issue introduced in CU8 where there is an increased IOPS write load that can cause mail delivery delays to the mailbox database. I’d recommend skipping CU10 and installing CU11, CU12, or newer as this issue was fixed in CU11.
- For convenience, here is the link to download the latest version of Exchange 2013.
- Instructions to Upgrade an existing Exchange 2013 to CU10.
- Remember on new deployments, you can deploy Exchange 2013 from the CU10 Rollup itself, saving time (walkthrough links above).
Important points to know when upgrading to Exchange 2010 CU10:
- CU10 does not upgrade the AD schema if you are already running CU7 or newer. That said, CU10 does extend RBAC which requires a change to the Configuration Partition of Active Directory.
- Due to the RBAC change, if you are running CU7 or newer you ares still required to run the following command using the extracted CU10 setup files prior to installing CU10: Setup.exe /PrepareAD /IAcceptExchangeServerLicenseTerms. Here is a link for additional detail on the CU10 upgrade process. Also, use that link if you are running a version of Exchange 2013 prior to CU7 for steps on the required AD Schema upgrade.
- If you set an HTTP redirect in Exchange 2013, you may need to re-do all those settings.