Microsoft Releases Emergency Windows 11 Update Following Patch Tuesday Bugs
Microsoft issued emergency Windows 11 update KB5129195 to fix Patch Tuesday regressions and fully close the CVE-2026-62721 privilege escalation flaw.
Microsoft shipped out-of-band cumulative update KB5129195 for Windows 11 24H2 and 25H2 (builds 26100.9457 and 26200.9457) after the September 8 Patch Tuesday rollup, which addressed over 960 CVEs including two actively exploited flaws, broke Remote Desktop Services, Hyper-V Plan9 folder sharing, and USB audio. The emergency release also strengthens the incomplete fix for CVE-2026-62721, an elevation-of-privilege flaw in the Windows User-Mode Power Service that could let a local attacker gain SYSTEM privileges. Companion patches cover Windows 11 26H1, Windows 10, and Windows Server. Some USB Audio Class 1.0 and AMD Radeon graphics issues remain unresolved.
- Emergency cumulative update KB5129195 targets Windows 11 24H2/25H2 builds 26100.9457 and 26200.9457.
- September Patch Tuesday addressed 960+ CVEs, 106 rated critical, with two actively exploited.
- Regressions broke Remote Desktop Services, Hyper-V Plan9 sharing, and USB audio devices.
- Update strengthens the incomplete fix for CVE-2026-62721, a UMPS flaw enabling SYSTEM-level access.
- USB Audio Class 1.0 and select AMD Radeon GPU issues remain unresolved.
- CVEs
- CVE-2026-62721
- Vendors
- Microsoft
- Products
- Windows 11Windows 10
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2026-62721 | Insufficient granularity of access control in User-Mode Power Service (UMPS) allows an authorized attacker to elevate privileges locally | 7.8 | <1% |
From the original article
4 min read at cybersecuritynews.com
Microsoft has pushed out an emergency, out-of-band Windows 11 update after its September Patch Tuesday release triggered a wave of stability failures across enterprise and consumer machines. The rushed fix, KB5129195, arrives less than a week after one of the largest security rollups the company has ever shipped, underscoring how quickly a massive patch can […]
By Guru Baran · cybersecuritynews.com
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