Deploy nowKB5129239OOB
It fixes actively exploited vulnerabilities. Deploy as soon as possible, and check the open known issues on your pilot devices first.
UrgencyCritical · 1 exploited
RiskModerate · 1 mitigated
KB5129239OOBOut-of-band release · 2026-09 OOB
Out-of-band release for Windows 10, version 1607 and Windows Server 2016
Is it safe to deploy?
2Windows versions
0CVEs fixed · 0 critical
0Exploited or in CISA KEV
1Open known issues affecting it
—Restart required (per MSRC)
Applies to
From Microsoft's release-information tables| Servicing branch | OS build | Release | Available |
|---|---|---|---|
| Windows 10, version 1607 | 14393.9514 | OOB 2026-09 OOB | 14 Sep 2026 |
| Windows Server 2016 | 14393.9514 | OOB 2026-09 OOB | 14 Sep 2026 |
Known issues in this update
Includes issues from the update it builds on- Mitigatedfrom KB5123099Win 10 1607, Server 2016updated 14 Sep USB audio devices might fail to start or produce no soundSome USB Audio Class 1.0 devices display Code 10 or fail in multichannel audio modes after installing KB5124008.
Issues this update resolves
- Resolvedfrom KB5124012fixed by KB5129194Win 11 26H1, Win 11 25H2, Win 11 24H2 +9updated 17 Sep Remote Desktop Services might stop responding after Sept. 2026 security updateSome Windows devices with Remote Desktop enabled might experience Remote Desktop Services (RDS) instability.
Security fixes
0 Microsoft CVEs · most urgent firstNo CVE fixes listed
MSRC lists no CVEs for this KB in the collected releases; preview (D) and out-of-band updates often carry no new security fixes.