This update also includes new daylight saving time (DST) updates for Exchange Server 2019. For more information about DST, see Daylight Saving Time Help and Support Center.

Known issues in this cumulative update

  • In multidomain Active Directory forests in which Exchange is installed or has been prepared previously by using the /PrepareDomain option in Setup, this action must be completed after the /PrepareAD command for this cumulative update has been completed and the changes are replicated to all domains. Setup will try to run the /PrepareAD command during the first server installation. Installation will finish only if the user who initiated Setup has the appropriate permissions.

    • About the /PrepareDomain operation in multidomain:

      The /PrepareDomain operation automatically runs in the Active Directory domain in which the /PrepareAD command is run. However, it may be unable to update other domains in the forest. Therefore, a domain administrator should run the /PrepareDomain in other domains in the forest.

    • About the permission question:

      Because the /PrepareAD is triggered in Setup, if the user who initiates Setup isn't a member of Schema Admins and Enterprise Admins, the readiness check will fail and you receive the following error messages.

      Error 1:

      The Active Directory schema isn't up-to-date, and this user account isn't a member of the 'Schema Admins' and/or 'Enterprise Admins' groups. For more informaion, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setipreadiness.SchemaUpdateRequired.aspx.


      Error 2:

      Global updates need to be made to Active Directory, and this user account isn't a member of the 'Enterprise Admins'group. For more information, visit: http://technet.microsoft.com/library(EXCHG.150)/ms.exch.setupreadiness.GlobalUpdateRequred.aspx.

  • Autodiscover Event ID 1 occurs after you install Cumulative Update 3 for Exchange Server 2019. For more information, see KB 4532190.

  • PDF preview function in OWA leads to download action unexpectedly. For more information, see KB 4583558.

  • Event IDs 1003, 1309 and 4999 are logged after installing Exchange Server 2019 CU8. For more information, see KB 5000631.

Issues that this cumulative update fixes

This cumulative update also fixes the issues that are described in the following Microsoft Knowledge Base articles:

  • 4588297 Attachments can't be downloaded or previewed from Outlook Web App

  • 4583531 Design change about inline images will be forced to download but not open in a new tab of OWA in Exchange Server 2019 and 2016

  • 4583532 ELC MRM archiving fails due to DomainName in AuthServer in Exchange Server 2019 and 2016

  • 4583533 Exchange Server 2019 or 2016 installation fails with error "The user has insufficient access rights"

  • 4583534 Event ID 65535 System.Runtime.Serialization errors in Application log in Exchange Server 2019 or 2016

  • 4583535 New-Moverequest, Resume-Moverequest, and Remove-Moverequest not logged in Audit logs in Exchange Server 2019 and 2016

  • 4583536 Set-MailboxFolderPermission is included in Mail Recipient Creation in Exchange Server 2019 and 2016

  • 4583537 Update Korean word breaker in Exchange Server 2019 and 2016

  • 4583538 Microsoft Teams REST calls exceed the default value of maxQueryStringLength in Exchange Server 2019 and 2016

  • 4583539 Non-breaking space is visible in message body in Outlook in Exchange Server 2019 and 2016

  • 4583542 Server assisted search in Outlook doesn't return more than 175 items in Exchange Server 2019

  • 4583544 Lots of LDAP requests for FE MAPI w3wp lead to DDoS on DCs in Exchange Server 2019

  • 4583545 Make DomainName in Authserver a multivalued parameter in Exchange Server 2019 and 2016

Get Cumulative Update 8 for Exchange Server 2019

Volume Licensing Center

To get Cumulative Update 8 for Exchange Server 2019, go to Microsoft Volume Licensing Center.

Note The Cumulative Update 8 package can be used to run a new installation of Exchange Server 2019 or to upgrade an existing Exchange Server 2019 installation to Cumulative Update 8.

File information

File hash information

File name

SHA1 hash

SHA256 hash

ExchangeServer2019-x64-cu8.iso

E9B06E81F67A68107ECDA43467EBA1C1263D62EB

1586B7504467E477845A141E85A1C4637EEFAF15FF6B3F362C25FB044712A897

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