Microsoft has published KB5066360, a hotpatch that updates Windows PowerShell on Windows 11 Enterprise LTSC 2024 to OS Build 26100.6569, addressing a specific PSDirect connectivity failure that could, under narrow conditions, allow unauthorized non-administrator access between host and guest virtual machines; the package is a hotpatch (no immediate reboot required for eligible devices) and was released on September 9, 2025.
Windows hotpatching is Microsoft’s mechanism to deliver narrow, security-focused fixes that take effect immediately without forcing the usual restart associated with cumulative updates. The model is intended for managed enterprise environments that prioritize uptime, and it depends on device eligibility (baseline alignment, licensing, VBS enabled, Intune enrollment and, for Arm64, CHPE disabled). These prerequisites and the quarterly cadence for baselines versus hotpatch months form the operational context for KB5066360. (techcommunity.microsoft.com)
Microsoft’s public KB for KB5066360 identifies two central themes: a targeted fix for PSDirect connections failing in hotpatch devices and a reminder about the broader Secure Boot certificate expiration program that organizations must plan for well before June 2026. The KB packages the PowerShell fixes with the servicing stack update where applicable and lists the files and file versions installed by the update.
Background
Windows hotpatching is Microsoft’s mechanism to deliver narrow, security-focused fixes that take effect immediately without forcing the usual restart associated with cumulative updates. The model is intended for managed enterprise environments that prioritize uptime, and it depends on device eligibility (baseline alignment, licensing, VBS enabled, Intune enrollment and, for Arm64, CHPE disabled). These prerequisites and the quarterly cadence for baselines versus hotpatch months form the operational context for KB5066360. (techcommunity.microsoft.com)Microsoft’s public KB for KB5066360 identifies two central themes: a targeted fix for PSDirect connections failing in hotpatch devices and a reminder about the broader Secure Boot certificate expiration program that organizations must plan for well before June 2026. The KB packages the PowerShell fixes with the servicing stack update where applicable and lists the files and file versions installed by the update.
What KB5066360 Actually Delivers
High-level summary
- Applies to: Windows 11 Enterprise LTSC 2024.
- Release date: September 9, 2025.
- Target OS Build after install: 26100.6569.
- Nature of update: Hotpatch — security-only fix that installs without an immediate restart on eligible devices and includes the servicing stack update where Windows Update is used. (support.microsoft.com, support.microsoft.com, bleepingcomputer.com, learn.microsoft.com, learn.microsoft.com, support.microsoft.com, learn.microsoft.com, support.microsoft.com)
- Confirm management and licensing: devices must be enrolled in Microsoft Intune (or Windows Autopatch) and the organization must hold an eligible license (E3/E5, Microsoft 365 Business Premium, Windows 365 Enterprise, etc..
- Verify VBS (Virtualization‑based Security) is enabled where required; validate firmware and Hyper‑V/VMM configuration for VBS support.
- For Arm64 devices: perform the one‑time CHPE disablement (via DisableCHPE CSP or registry HotPatchRestrictions) and reboot once before attempting hotpatch enrollment. Document the change and test unaffected x86 emulation workloads.
Pilot and validation
- Create a pilot group of representative devices in Intune and enable a Windows quality update policy with Hotpatch set to Allow. Deploy KB5066360 to the pilot group first. Monitor for process/service anomalies, driver logs, EDR alerts and application behavior for 7–14 days.
- Validate PSDirect, PSRemoting, and VM guest/host interaction scenarios specifically, since this hotpatch targets PSDirect-related behavior. Include virtualization stack vendors (Hyper‑V, VMM) and backup vendors in test plans. (support.microsoft.com, learn.microsoft.com, techcommunity.microsoft.com, support.microsoft.com, support.microsoft.com, techcommunity.microsoft.com)
Source: Microsoft Support KB5066360—Security Update for Windows PowerShell on Windows 11 Enterprise LTSC 2024 (Hotpatch) - Microsoft Support
