Due to the seriousness of the vulnerabilities listed in MS #KB50000871 the UBX Cloud team has created this guide to assistant our IT/MSP partners.

These are the steps applicable to patching Exchange Server 2016 to the latest cumulative update CU19 as of the article post date.

Download offline package for .NET Framework 4.8

Download offline package for VC++ redistributable

Download Exchange 2016 CU ISO | (Alternate Download) |

Reboot Existing Exchange Server

Run this in Exchange powershell

Set-OrganizationConfig -MapiHttpEnabled $true

Mount Exchange ISO to existing Exchange 2016 or 2019 server

Once schema is extended run setup.exe from ISO and follow the prompts once completed.

Setup.exe /PrepareSchema /IAcceptExchangeServerLicenseTerms

Reboot the Exchange server and apply the security patch