January 2023 Exchange Server Security Updates

Microsoft Exchange Servers security updates have been released for January 2023.

These updates are available for the following specific versions of Exchange Server:

Exchange Server 2013 CU23 SU19
Exchange Server 2016 CU23 SU5
Exchange Server 2019 CU11 SU9 & CU12 SU5

The recommendation is to install these updates immediately to protect your environment.
In the scenario where you do a Cumulative Update(CU), you need to make security updates. Otherwise, remember that you have to do the Cumulative Update(CU) first and then the Security Update(SU).

Inventory your Exchange Servers to determine which updates –> “Exchange Server Health Checker
Choose your current CU and your target CU to get directions –>  “Exchange Update Wizard
If you encounter errors during or after installation of Exchange Server –> “Exchange Setup Assist

Recommended Action :

  • Enable certificate signing of Powershell serialization payload
  • To defend Exchange Servers against attacks on serialized data, added certificate-based signing of PowerShell serialization payloads.
  • If you have a server running Microsoft Exchange Server 2013 in your environment, we recommend that you don’t turn on serialization payload signing for now.
  • In the first stage of rollout, this new feature must be manually enabled by an Exchange Server admin due to feature dependencies.
  • You can use to validate/create the required auth certificate


Note: Don't double-click the 'MSP file' to run it. Run Command Prompt (not Powershell) as an Administrator.


Have a nice day!