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.
Researchers Turn USB Auto-Install Into a Full SYSTEM Takeover on Windows 11
DEF CON researchers chained Windows Plug and Play auto-install abuse with third-party driver flaws to reach SYSTEM on fully updated Windows 11.
In 'Plug And Pwn' research prepared for DEF CON 34, Alejandro Hernando and Borja Martinez emulated USB devices so Windows auto-installed signed vendor software, chaining a Sierra Wireless SwiService.exe SetDNS primitive, a Sony FeliCa co-installer path-traversal flaw that writes a DLL into System32, and device reconnection for SYSTEM code execution. A remote variant over Remote Desktop forges a synthetic Intel RealSense device and abuses a CRYPTBASE.dll search-order hijack when PnP or low-level USB redirection is enabled. Microsoft notes RDP does not allow supported PnP and RemoteFX USB redirection by default, and no in-the-wild exploitation has been reported.