Microsoft has released Security Updates (SUs) for vulnerabilities found in:
Exchange Server 2013
Exchange Server 2016
Exchange Server 2019
SUs are available in a self-extracting auto-elev...
Updated Mar 03, 2023
Version 13.0
Blog Post
chrlie Interesting that you were able to narrow it down to a specific addin. We don't really have any user specific addins outside the Dynamics 365 App for Outlook that gets pushed out from Dynamics 365. Users that don't get that addin that aren't Dynamics users are affected by this bug for us. In case it helps anyone here are a few screenshots of the addins we have in Exchange, the list of the add-ins for a mailbox not affected, and then a powershell screenshot of what happens when I try to do get-app -mailbox user. For us, it seems like most people are affected by this, I finally found a couple mailboxes that the get-app cmdlet worked on and confirmed they are able to view their addins in OWA.
All org addins from EAC:
All Org add-ins from EAC
Manage add-ins from a working mailbox
OWA list of addins on a working mailbox
Powershell error when you try to list the apps for affected mailboxes along with a working one
Results from get-app in powershell. Confirmed same error on all 3 Exchange servers