Summary
- Microsoft has published the September 2026 Windows Scan Cab (wsusscn2.cab) for offline update compliance scanning.
- This affects only environments that use Scan Cab/WSUS offline scanning to determine whether Windows security updates are needed.
- The current Scan Cab does not include metadata for Microsoft Office update KB5002923; Microsoft says an additional Scan Cab will be released later to cover it.
- Admins can download and deploy the updated Scan Cab through their normal update compliance processes.
- No action is needed if your organization does not use Scan Cab, though Microsoft notes some third-party tools may rely on it.
Microsoft 365 Message Center ID: MC1469525
Primary Service: Windows
Admin Impact: Medium
User Impact: Low
Release Start: 08 Sept 2026
Release End: 08 Sept 2026
Last Modified: September 10, 2026
Category: Prevent or fix issues
Tags: New feature
Status: Launched
Products & Platforms: Windows
History
Updated September 10, 2026: The September 2026 Scan Cab includes metadata for Microsoft Office update (KB5002923). An earlier version of this notice incorrectly stated that it did not and that an additional Scan Cab would follow soon — no additional Scan Cab will be released. Deploy the September 2026 Scan Cab as normal; no further action is required.
9/8/2026 Item Added to Message Center
Microsoft Message
IMPORTANT : This notice only affects environments where Scan Cab is used to check for update compliance.
The September 2026 Scan Cab was made available at 2:00 PM PDT today, September 8, 2026. It helps determine whether a Windows device needs security updates without connecting to the Windows Update service.
Note: This Scan Cab does not include metadata for Microsoft Office update (KB5002923). An additional Scan Cab covering it will follow. Deploy the September 2026 Scan Cab now, and deploy the new Scan Cab when it becomes available.
Rollout schedule
The September 2026 Scan Cab is available now. An additional Scan Cab with metadata for KB5002923 will follow, with timing communicated as more information becomes available.
Who is affected
The Wsusscn2.cab file is a cabinet file that is signed by Microsoft and contains information about Microsoft security-related updates. Devices that aren’t connected to the Internet can be scanned to see whether these security-related updates are present or required. The Wsusscn2.cab file doesn’t contain the security updates themselves so you must obtain and install any needed security-related updates through other means.
What will happen
You can download and deploy the September 2026 Scan Cab via the usual processes. For detailed guidance, see the Additional information section below.
No action is required on environments where Scan Cab is not employed. However, please note that there might be non-Microsoft applications which utilize Scan Cab. Review the documentation for any software and update deployment tools used in your organization to understand if this is applicable in your environment.
Additional information
- Updated Scan Cab: Download the new Scan Cab here
- Announcing a smaller WSUS Scan Cab: Learn more about WSUS and the Scan Cab process
- Using WUA to Scan for Updates Offline: Windows Update Agent (WUA) can be used to scan computers for security updates without connecting to Windows Update
- WSUS and the Catalog Site: The Catalog Site used by WSUS to import updates and drivers