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As always, test these updates in a lab first! I recommend checking out this 7-part guide on configuring Exchange in your lab. It doesn’t take much to get one going.
The updates are as follows:

Exchange 2019 Cumulative Update 7 (VLSC)| KB4571787

Exchange 2016 Cumulative Update 18 | KB4571788 | UM Language Pack
So, what’s new in this Cumulative Update?
Microsoft has resolved a number of issues with the Exchange 2019 Sizing Calculator. I actually ran into one of these myself where the transport database size estimate (under the Role Requirements tab) always reported a 0 GB size per server. This issue has now been fixed in version 10.5 of the calculator (included with the Exchange 2019 CU7 ISO in the Support folder). Be sure to ditch v10.4.

These series of cumulative updates also resolves an issue where Surface Hub would connect to meetings with the wrong communications client (Skype or Teams) if both clients were installed on the device.
A couple of other items of note is that this cumulative update will fix an issue where the MAPI App Pool could become locked and drive CPU to 100% for over an hour and resolves the security issue CVE-2020-16875, which addresses a remote code execution vulnerability.
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