https://support.microsoft.com/en-us/help/4458871/cumulative-update-3-for-sql-server-2016-sp2
This page says there's a problem with a fix in this release, but Microsoft doesn't tell us what the issue is or what we should be looking for. Is there any other documentation that tells where this problem is, what to look for and if we need to back out this CU? It just went into a couple of my production systems last night.