Cumulative Update 15 for Microsoft Exchange Server 2019 was released on February 10, 2025. It includes fixes for nonsecurity issues and all previously released fixes for security and nonsecurity issues. These fixes will also be included in later cumulative updates for Exchange Server 2019.
Extended Protection is enabled by default for Exchange Server 2019. For more information about Extended Protection, see Configure Windows Extended Protection in Exchange Server. For more information about prerequisites for enabling or disabling Extended Protection, see CU15 Announcement blog post.
Note
Exchange Server 2019 CU15 cannot be installed in an organization that has any servers running Exchange 2013. You must deactivate and uninstall all Exchange 2013 servers from your organization before you install CU15.
Features introduced in this update
- Support for Windows Server 2025
- Partial TLS 1.3 support for Exchange Server 2019
- Certificate management tasks restored to EAC
- Feature Flighting in Exchange Server
- OIT module in Exchange Server is replaced by DocParser
Issues that this cumulative update fixes
This cumulative update also fixes the issues that are described in the following Microsoft Knowledge Base articles:
- 5047359 Clean up old Exchange OWA files automatically to free up disk space
- 5047361 Inline images and text attachments are not visible in OWA
- 5047402 Online Archiving bypasses the InternetWebProxy setting in Exchange 2019
- 5047995 MFNs are not sent to remote domains
- 5047997 Wrong server version displayed in POP and IMAP logoff strings
- 5048017 RecoverServer operation fails in Exchange Server 2019
- 5048019 "NullReferenceException" error and Managed Store stops responding
- 5048020 Calendar print doesn't work in OWA from Exchange 2019 CU14 onwards
- 5048021 HTML message is corrupted if <"e;> is included
- 5048072 "Enabled Extended Protection" message when you run setup with prepare* command
- 5047994 German umlauts in the Subject are replaced by a question mark
- 5047358 Group Metrics generation doesn't finish in multidomain environment
Known issues in this cumulative update
- The Edge Transport service (EdgeTransport.exe) stops responding and then restarts. For more information and a workaround, see Edge Transport service stops responding after installing November 2024 SU or Exchange 2019 CU15.
Get Cumulative Update 15 for Exchange Server 2019
Method 1: Volume Licensing Center
To get Cumulative Update 15 for Exchange Server 2019, go to Microsoft Volume Licensing Center..
Note: The Cumulative Update 15 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 15.
Method 2: Microsoft Download Center
You can get the standalone update package through the Microsoft Download Center.
Microsoft Exchange Server 2019 Cumulative Update 15 - Download the package now
Cumulative update information
Prerequisites
For more information about the prerequisites to set up Exchange Server 2019, see Exchange 2019 prerequisites.
Restart requirement
You might have to restart the computer after you apply this cumulative update package.
Registry information
You don't have to make any changes to the registry after you apply this cumulative update package.
Removal information
After you install this cumulative update package, you can't uninstall the package to revert to an earlier version of Exchange Server 2019. If you uninstall this cumulative update package, Exchange Server 2019 is removed from the server.
File information
File hash information
| File name | SHA256 hash |
|---|---|
| ExchangeServer2019-x64-cu15.iso | 07C3FC1627DDE4B88CB8D25EAB5F16923CC12DAC014E5965B633FAC8FCA629AE |
More information
For more information about the deployment of Exchange Server 2019, see Release notes for Exchange Server 2019.
For more information about the coexistence of Exchange Server 2019 and earlier versions of Exchange Server in the same environment, see Exchange Server 2019 system requirements.
For more information about other Exchange updates, see Exchange Server Updates: Build numbers and release dates.
References
Learn about the terminology that Microsoft uses to describe software updates.