Exchange 2019 CU9 and Exchange 2016 CU20

Cumulative Update 9 for Exchange 2019 is now available as well as Cumulative Update 20 for Exchange 2016.

They both contain the same 12 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 CU for Exchange 2019 contains 3 additional fixes which did not apply to Exchange 2016.

Notable improvements, changes and fixes are;

  • Includes the security updates to mitigate the zero-day vulnerabilities (HAFNIUM) which were released earlier this month.
  • KB5001184 EAC has no option to select the correct tenant for an Office 365 mailbox.
  • KB5001188 Incorrect MRM properties stamped on mail item delivery when sending to multiple mailboxes on the same database.
  • KB5001192 Microsoft Teams fails to show calendar due to Autodiscover v2 isn’t site aware.
  • KB5001195 UPN specified when creating mailbox is overwritten automatically causing login failures.
  • KB4583558 PDF preview function in OWA leads to download action unexpectedly.
  • KB5001181 Certain search scenario can’t return expected result in Outlook online mode in Exchange Server 2019.
  • 5000631 Event IDs 1003, 1309 and 4999 are logged after installing Exchange Server 2019 CU8.

This release includes no new updates to the Active Directory Schema for Exchange 2019 and Exchange 2016.
The next planned quarterly update is in June 2021. That will be the last planned CU for Exchange 2016.

Exchange 2019: CU9 KB4602570VLSC Download
Exchange 2016: CU20 KB4602569DownloadUM Language Pack
View: Blog post of the Exchange Team about CU9 for Exchange Server 2019 and CU 20 for Exchange 2016.