Windows Server · 2025 · Release · Security update (Patch Tuesday)

September 9, 2025—KB5065426 (OS Build 26100.6584)

Windows Server 2025: Current LTSC release

Microsoft's known issues — KB5065426

  • Issue Known issue Symptoms We are aware of an edge case affecting hotpatched devices that have installed the September 2025 Hotpatch update ( KB5065474 ) or the September 2025 security update ( KB5065426 ). These devices might experience failures with PowerShell Direct (PSDirect) connections when the host and guest virtual machines (VMs) are both not fully updated. When a patched guest VM attempts to connect to an unpatched host (or vice versa), the system is expected to fall back to a legacy handshake and clean up the socket gracefully. However, this fallback mechanism fails intermittently, resulting in socket cleanup issues. The connection failure might appear random, and users might observe Event ID 4625 l Workaround: This issue is addressed in KB5066360 . If your hotpatched device is experiencing issues with PSDirect connection, we recommend updating both the host and guest VM with these updates. This issue is addressed in KB5066835 . This issue is addressed KB5068861 . This issue is addressed in KB5068861 .

Microsoft's release notes for KB5065426 ›

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