Microsoft has released security updates (SUs) for vulnerabilities found in:
Exchange Server 2013
Exchange Server 2016
Exchange Server 2019
IMPORTANT: Starting with this release of Securit...
Updated May 27, 2022
Version 21.0
Blog Post
I experienced two different problems with this SU installation and Exchange 2016.
In our test environment, we were running CU22, and the SU for CU22 was installed successfully via SCCM. I then downloaded and installed CU23. Allowing SCCM to then install the SU for CU23 failed and left all Exchange services (plus a few others) in a Disabled startup state. I had to set the services to Automatic (as needed) and reboot the server to get it running. This happened twice. I then downloaded the SU for CU23 and installed it successfully. The test server is a VM and a bit underpowered (2 CPUs and 12GB RAM) if that makes a difference.
In our prod environment, we are still running CU22 and the SU for CU22 installed successfully via SCCM. Healthchecker.ps1 tells us we need to run setup with /PrepareAllDomains, but when I try to do that, I'm told a reboot is pending from a previous installation. I've rebooted one of my Exchange servers twice now and another one once, but I still get that message when I try to run setup.
I will schedule a CU23 install in prod and then the SU for CU23 immediately after. I'll then try once again to run setup with /PrepareAllDomains.