Microsoft has released security updates (SUs) for vulnerabilities found in:
Exchange Server 2013
Exchange Server 2016
Exchange Server 2019
IMPORTANT: Updates are released in a self-extrac...
Updated Aug 11, 2022
Version 8.0
Blog Post
LukasSMSFT
Microsoft
Microsoftspring8080 we've announced a service model change with the 2022H1 release. New Cumulative Updates will be released twice a year.
I assume (based on the information that you plan to install CU23) that you're using Exchange 2016.
Exchange Server 2013 and 2016 are out of mainstream support (https://docs.microsoft.com/en-us/lifecycle/products/exchange-server-2016) and the next CU (2022H2) will be for Exchange Server 2019 only (see: https://techcommunity.microsoft.com/t5/exchange-team-blog/released-2022-h1-cumulative-updates-for-exchange-server/ba-p/3285026).
As Exchange 2016 is in extended support, you should install it. We've also fixed multiple issues with the latest CU: https://support.microsoft.com/en-us/topic/cumulative-update-23-for-exchange-server-2016-kb5011155-98183ada-e4cd-465f-b201-69d40fb74678
I'd encourage you to follow these best practices for installing a CU: https://docs.microsoft.com/en-us/exchange/plan-and-deploy/install-cumulative-updates?view=exchserver-2019#best-practices