Cumulative Update 23 for Exchange Server 2013

Applies to: Exchange Server 2013

Cumulative Update 23 for Microsoft Exchange Server 2013 was released on June 18, 2019. This cumulative update 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 2013.

This update also includes new daylight saving time (DST) updates for Exchange Server 2013. For more information about DST, see Daylight Saving Time Help and Support Center.

Known issues

The Set-SendConnector cmdlet does not work for Exchange Server 2013 in hybrid scenarios that have a Edge server installed. For more information, see KB 4523519

Issues that this cumulative update fixes

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

4502131 "TLS negotiation failed with error UnknownCredentials" error after updating TLSCertificateName on Office 365 send connector in Exchange Server 2013 hybrid environment

4503028 Description of the security update for Microsoft Exchange Server 2013 and 2010: June 11, 2019

Get Cumulative Update 23 for Exchange Server 2013

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  • You can use the Cumulative Update 23 package to run a new installation of Exchange Server 2013 or to upgrade an existing Exchange Server 2013 installation to Cumulative Update 23.
  • You do not have to install any previously released Exchange Server 2013 cumulative updates or service packs that were released before Cumulative Update 23 before you install Cumulative Update 23.

Cumulative update information


This cumulative update requires Microsoft .NET Framework 4.7.2.

A component that's used within Exchange requires a new Visual C++ prerequisite to be installed with Exchange Server. The prerequisite can be downloaded at Visual C++ Redistributable Packages for Visual Studio 2013. For more information, see KB 4295081.

The setup process for Exchange Server 2013 identifies any missing prerequisites. For more information about the prerequisites for the setup of Exchange Server 2013, see Exchange 2013 prerequisites.

Restart requirement

You may have to restart the computer after you apply this cumulative update package.

Registry information

You do not 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 2013. If you uninstall this cumulative update package, Exchange Server 2013 is removed from the server.

More information

For more information about the deployment of Exchange Server 2013, see Release Notes for Exchange 2013.

For more information about the coexistence of Exchange Server 2013 and earlier versions of Exchange Server in the same environment, see Exchange 2013 System Requirements.

For more information about other Exchange updates, see Exchange Server Updates: Build numbers and release dates.


Learn about the terminology that Microsoft uses to describe software updates.