Exchange 2019 CU11 and Exchange 2016 CU22

Cumulative Update 11 for Exchange 2019 is now available as well as Cumulative Update 22 for Exchange 2016.

They both contain the same 15 documented new fixes or improvements, as well as all previously released fixes and security updates for their respective Exchange version and the latest DST updates. The Exchange 2019 CU also contains 4 unique fixes which do not apply to the Exchange 2016.

Major changes to be aware of before installing these CU;

  • A new service will be installed; Microsoft Exchange Emergency Mitigation service (or shortened; EM service).
    Once an hour, this service checks for mitigations to known security threats. It can then directly implement these pre-configured settings on the Exchange server to mitigate the threat until a Security Update can be applied. For more info see this blog post by the Exchange Team and this Microsoft Docs article.
  • The IIS URL Rewrite module (x64 installer) must be installed before installing this CU. This is a requirement for the EM service.
  • When using the unattended setup, note that the /IAcceptExchangeServerLicenseTerms switch will no longer work. Instead, you’ll need to use the (even longer) /IAcceptExchangeServerLicenseTerms_DiagnosticDataON or /IAcceptExchangeServerLicenseTerms_DiagnosticDataOFF switch.

Other notable improvements, changes and fixes are;

  • KB5006983: Exchange Server 2019 and 2016 certificates created during setup use SHA-1 hash.
  • KB5006986: Opening an Outlook message from the desktop removes line spacing.
  • KB5006988: Export of .pst file is unexpectedly triggered again in Exchange Server 2019 and 2016.
  • KB5006993: Can’t log on to OWA in Chrome if SSL is offloaded in Exchange Server 2019 and 2016.
  • KB5006994: BCC values not retained in Sent Items in a shared mailbox in Exchange Server 2019 and 2016.

This release does not include new updates to the Active Directory Schema for Exchange 2019 nor Exchange 2016.
The next planned quarterly update for Exchange 2019 is in December 2021. No new update for Exchange 2016 is planned at this moment.

Exchange 2019: CU11 KB5005334Download
Exchange 2016: CU22 KB5005333DownloadUM Language Packs
View: Blog post of the Exchange Team about CU11 for Exchange Server 2019 and CU 22 for Exchange 2016.