Tuesday, May 10, 2022

Released: May 2022 Exchange Server Security Updates

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 Security Updates, we are releasing updates in a self-extracting auto-elevating .exe package (in addition to the existing Windows Installer Patch format). Please see this post for more information. Original update packages can be downloaded from Microsoft Update Catalog.

These SUs are available for the following specific builds of Exchange Server:

The SUs address vulnerabilities responsibly reported to Microsoft by security partners and found through Microsoft’s internal processes. Although we are not aware of any active exploits in the wild, our recommendation is to immediately install these updates to protect your environment.

These vulnerabilities affect Exchange Server. Exchange Online customers are already protected from the vulnerabilities addressed in these SUs and do not need to take any action other than updating any Exchange servers in their environment.

More details about specific CVEs can be found in the Security Update Guide (filter on Exchange Server under Product Family).

Manual run of /PrepareAllDomains is required

Because of additional security hardening work for CVE-2022-21978, the following actions should be taken in addition to application of May 2022 security updates:

Latest version of Exchange Server installed in the organization

Additional steps needed

Exchange Server 2016 CU22 or CU23, or

Exchange Server 2019 CU11 or CU12

Install the May 2022 SU first and then run the following Command Prompt command once using Setup.exe in your Exchange Server installation path (e.g., …\Program Files\Microsoft\Exchange Server\v15\Bin):


“Setup.exe /IAcceptExchangeServerLicenseTerms_DiagnosticDataON /PrepareAllDomains”




“Setup.exe /IAcceptExchangeServerLicenseTerms_DiagnosticDataOFF /PrepareAllDomains”

Exchange Server 2013 CU23

Install the May 2022 SU first and then run the following Command Prompt command once using Setup.exe in your Exchange Server installation path (e.g., …\Program Files\Microsoft\Exchange Server\v15\Bin):


Setup.exe /IAcceptExchangeServerLicenseTerms /PrepareAllDomains

Any older version of Exchange Server not listed above

Update your Exchange server to the latest CU, install May 2022 SU and then follow the steps above.

You need to run /PrepareAllDomains only once per organization and those changes will apply to all versions of Exchange Server within the organization. When you run /PrepareAllDomains, your account needs to be a member of the Enterprise Admins security group. This might be a different account from the one you use to install the SU. 

Update installation

Two update paths are available:


Inventory your Exchange Servers / determine which updates are needed

Use the Exchange Server Health Checker script (use the latest release) to inventory your servers. Running this script will tell you if any of your Exchange Servers are behind on updates (CUs and SUs).

Update to the latest Cumulative Update

Go to https://aka.ms/ExchangeUpdateWizard and choose your currently running CU and your target CU to get directions for your environment.

If you encounter errors during or after installation of Exchange Server updates

If you encounter errors during installation, see the SetupAssist script. If something does not work properly after updates, see Repair failed installations of Exchange Cumulative and Security updates.

Known issues with this release

We are not aware of any known issues with this release.

Issues resolved by this release

The following issues have been resolved in this update:

  • Exchange Service Host service fails after installing March 2022 security update (KB5013118)
  • New-DatabaseAvailabilityGroupNetwork and Set-DatabaseAvailabilityGroupNetwork fail with error 0xe0434352
  • The UM Voicemail greetings function stops working and returns error 0xe0434352.
  • Unable to send mails through EAS and Get-EmailAddressPolicy fails with Microsoft.Exchange.Diagnostics.BlockedDeserializeTypeException after installing Security Update KB5008631 for Exchange 2019


My organization is in Hybrid mode with Exchange Online. Do I need to do anything?
While Exchange Online customers are already protected, the May 2022 SUs do need to be installed on your on-premises Exchange servers, even if they are used only for management purposes. You do not need to re-run the Hybrid Configuration Wizard (HCW) after installing updates.

Do I need to install the updates on ‘Exchange Management Tools only’ workstations?
Servers or workstations running only the Management Tools role (no Exchange services) do not need these updates. If your organization uses only an Exchange Management Tools machine, then you should install the May 2022 SU package on it and run /PrepareAllDomains as per the above instructions to update Active Directory permissions.

Instructions seem to indicate that we should /PrepareAllDomains after May 2022 SU is installed; is that correct?
Yes. The May 2022 SU package updates files in Exchange server folders when it is installed. That is why once those files are updated (SU is installed) – we ask you to go and explicitly /PrepareAllDomains using setup from \v15\Bin folder.

NOTE: This post might receive future updates; they will be listed here (if available).

The Exchange Server Team

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