A recent security update for Windows 10 22H2, Windows Server 2019, and Windows Server 2016 is causing disruptions in enterprise applications utilizing the MSMQ service. Businesses are recommended to reach out to Microsoft support for guidance on mitigating these issues.
What Has Changed
The December 2025 security updates introduced changes to the MSMQ security model, particularly affecting NTFS permissions on C:\Windows\System32\MSMQ\storage. This has led to MSMQ users requiring write access to a directory ordinarily limited to administrators.
These changes have resulted in inactive MSMQ queues, application errors when writing to queues, and IIS site failures with insufficient resource errors. Additionally, users are receiving misleading messages about disk space or memory shortages.
Impact on Windows Versions
The issue impacts enterprise systems running the latest security updates on Windows 10 22H2, Windows Server 2019, and Windows Server 2016. However, individuals on Windows Home or Pro versions are typically unaffected by this issue.
Attempts to utilize MSMQ APIs are failing, especially in clustered environments under heavy loads. Microsoft's investigation into the issue is ongoing, but a concrete timeline for a resolution has not been disclosed.
Advice for Businesses
- Companies experiencing issues should contact Microsoft business support for temporary solutions.
- Consider rolling back the recent updates if problems persist.
For many enterprise users, the temporary workaround from Microsoft support may be essential until a permanent fix is provided. Monitoring Microsoft's updates for further solutions is advisable.
