The Update BureauKB5078938: Cumulative update for Windows 10, version 1607, March 2026. Secure Boot certificate targeting expands; catalog warning added
Secure Boot certificate targeting now covers more eligible devices, and Windows System Image Manager warns users to confirm a catalog is trusted. The update addresses 35 Important vulnerabilities.
Does it affect you? Applies to: Devices running Windows 10 version 1607: Enterprise LTSB 2016 and IoT Enterprise 2016 LTSB editions.
Microsoft publishes separate notes for this KB for Windows Server.
What changes
Improvement 1 change
Secure Boot
For: Devices eligible for new Secure Boot certificates
-
More eligible devices can receive new Secure Boot certificates automatically, through a controlled, phased rollout.1
Targeting uses additional high-confidence device data, primarily device diagnostic data. Devices receive certificates only after showing sufficient successful update signals; servers are unlikely to qualify because data is limited, but are not explicitly excluded.
New feature 1 change
Windows System Image Manager
For: Windows System Image Manager users
- A warning dialog helps you confirm that a selected catalog file comes from a trusted source.2
Technical details
Data sheet · Security · Downloads · Components Click to collapse or expand
Data sheet
- Released
- 2026-03-10
- Classification
- Security Updates
- Type
- Cumulative update
- Restart
- Required
- Replaces
- KB5075999, KB5073722, KB5074974, KB5071543
- Replaced by
- KB5082198
| Version | Build | Channel |
|---|---|---|
| 1607 | 14393.8957 | General availability |
Security
| Vulnerability | Severity | CVSS |
|---|
The table lists the 0 exploited, publicly disclosed or critical vulnerabilities. See all 35 vulnerabilities →
Downloads (Microsoft Update Catalog)
Updated components
383 files changed since the previous update for the same versions.
| Top changed components | Files |
|---|---|
| Graphics and display | 16 |
| Networking | 10 |
| Search | 10 |
| File Explorer and shell | 8 |
| Security and sign-in | 8 |
| Settings | 6 |
| Storage and file systems | 6 |
| Hyper-V and virtualization | 5 |
| Kernel | 4 |
| Secure Boot | 4 |
| Bluetooth | 2 |
| Remote Desktop | 2 |
Verified in package: changed files confirm Secure Boot.
Sources
Cited passages from Microsoft's official notes (2)
-
1.
With this update, Windows quality updates include additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates.
support.microsoft.com -
2.
This update adds a warning dialog to help users confirm that the selected catalog file comes from a trusted source.
support.microsoft.com
Checked automatically: 7 of 8 checks passed, 2 quoted passages · compared with Microsoft's page on Sep 25, 2026
- Quotes found in the official pages: passed
- Numbers found in the sources: passed
- Vulnerabilities from the dossier only: passed
- Links to allowed domains only: passed
- Every official change covered: passed
- Readable plain text: passed
- Changes confirmed by the file list: passed
- Sources agree: not passed
A second AI read the text against the sources: correctness 5/5, clarity 4/5, completeness 5/5. How we work
Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake