Microsoft has released Security Updates (SUs) for vulnerabilities found in:
Exchange Server Subscription Edition (SE)
Exchange Server 2019
Exchange Server 2016
SUs are available for the f...
Updated Jul 24, 2026
Version 2.0
Blog Post
In the "Rollback procedures for released mitigations" section on this page: https://learn.microsoft.com/en-us/Exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-emergency-mitigation-service#rollback-procedures-for-released-mitigations
Why is the header called M2 when the mitigation applied is called M2.1.0 ?
MitigationsApplied : {PING1, M2.1.0}
Nino_Bilic
Microsoft
MicrosoftMitigations could have "versions" or "revisions" hence the numbers after "2". In this case, that did not really get used (but the capability is there) but when working with the specific mitigation it needs to be referenced specifically. So we would not use "M2.anything" for a different mitigation if we needed to release one let's say next year (or whatever) it would be M3.something.