KB5044062 is the November 2024 security update for Microsoft Exchange Servers. It was released on 12 November 2024.
Early adopters of KB5044062 have reported encountering issues after installing the security update on Exchange servers. The issues eventually cause transport rules to fail and brings down the mail functionality on the servers.
Updated – 28 November 2024 – Microsoft re-released the cumulative update for Exchange Servers 2016 and 2019. The revised update resolves the transport rules issue reported after installing KB5044062. You can refer to the KB5049233 notes for further action.
Microsoft has paused the rollout of the security update KB5044062 on Exchange Servers for now. We run through the issue experienced on Exchange servers below.
As of 21 November, 2024, the security update for Exchange servers (KB5044062) remains unavailable. We would update this document once the update has been released once again.
You can also check the Microsoft Community thread. Other system administrators may shared experiences after installing KB5044062.
What versions of Exchange Servers are impacted?
KB5044062 pertains to the following versions:
- Microsoft Exchange Servers 2019 Cumulative Update 14
- Microsoft Exchange Servers 2019 Cumulative Update 13
- Microsoft Exchange Servers 2016 Cumulative Update 23
All the stated versions of Exchange servers are impacted by the post-deployment issues.
Exchange issue description
Upon installation of KB5044062 on Exchange servers, the Transport rules on the server fail periodically. Microsoft has confirmed that the issue of failing transport rules affects Exchange customers who use their own transport or DLP rules. Microsoft is investigating the issue in detail. We expect a resolution to be provided in the near future.
It may be pertinent to mention that the issue does not affect customers who might not use Transport or DLP rules. On a similar note, customers who did not run into the issue with rules, can continue using the November SU update.
Remediation
As of now, the issue resulting out of installation of security update for Exchange services does not have a fix. Microsoft is investigating the issue and it hopes to provide a resolution soon.
Until a resolution is finalized, Microsoft suggests uninstalling KB5044062 from Exchange Servers 2019 and 2016.
On its own, Microsoft has paused the automatic rollout of the KB5044062 security update. The security update is no longer available for ready download from the Microsoft site.
We will update this note once Microsoft has provided a resolution or made the security update available for installation.
For a list of problems experienced by Exchange admins after installing KB5044062, you may check the Reddit thread on this page.
Rajesh Dhawan is a technology professional who loves to write about Cyber-security events and stories, Cloud computing and Microsoft technologies. He loves to break complex problems into manageable chunks of meaningful information.