Microsoftは9月9日(現地時間)、毎月米国時間の第2火曜日に提供している月例更新の一環として、Windows 11 Version 24H2用の累積アップデートKB5065426と、Windows 11 Version 23H2/22H2用の累積アップデートKB5065431をリリースしました。
更新プログラムは主にシステムの品質を改善し、セキュリティ問題を修正するものです。
自動的にインストールされますが、Windows UpdateまたはMicrosoft Update Catalogを利用して手動でインストールすることもできます。
それぞれの変更点は以下の通りです(キュリティアップデートの内容は日本Microsoftのブログで参照できます)。
September 9, 2025—KB5065426 (OS Build 26100.6584)
Windows 11 Version 24H2用の更新プログラムKB5065426では、8月29日に公開されたKB5064081の内容に加え、予期せぬUACプロンプトが表示される問題の修正や、SMB監査機能の強化、特定の入力方式でアプリが無反応になる問題を修正、NDI使用時にDisplay Captureを有効にすると音声が途切れる問題の修正などが行われています。
リリースノートは以下の通りです。
ハイライト
This update addresses security issues for your Windows operating system.
改良と修正
[App compatibility (known issue)] Fixed: Addresses an issue that caused non-admin users to receive unexpected User Account Control (UAC) prompts when MSI installers perform certain custom actions. These actions might include configuration or repair operations in the foreground or background, during the initial installation of an application.
This issue could prevent non-admin users from running apps that perform MSI repairs, including Office Professional Plus 2010 and multiple applications from Autodesk (including AutoCAD). This fix reduces the scope for requiring UAC prompts for MSI repairs and enables IT admins to disable UAC prompts for specific apps by adding them to an allowlist.
For more information, see Unexpected UAC prompts when running MSI repair operations after installing the August 2025 Windows security update.
[File server] This update enabled auditing SMB client compatibility for SMB Server signing as well as SMB Server EPA. This allows customers to assess their environment and identify any potential device or software incompatibility issues before deploying the hardening measures that are already supported by SMB Server. For detailed guidance, see CVE-2025-55234.
[Input]
Fixed: This update addresses an issue that caused certain apps to stop responding input in some input method scenarios.
Fixed: This update addresses an issue that caused some Internet Information Services (IIS) modules to disappear from IIS Manager, preventing users from configuring IIS using the IIS Manager interface.
[Networking (known issue)] Fixed: This update addresses an issue that affects audio in apps using the Network Device Interface (NDI). Audio stutters when Display Capture is on in OBS Studio Application. This can occur after installing KB5063878.
既知の不具合
更新プログラムには以下の1件の既知の不具合が存在します。
PSDirect connections failing in hotpatched devicesSymptoms
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 logged in the Security Event log within Windows Event Viewer.
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.
更新プログラムはWindows Updateの他、Microsoft Update Catalog、Windows Server Update Services(WSUS)を利用してインストールすることができます。
September 9, 2025—KB5065431 (OS Builds 22621.5909 and 22631.5909)
Windows 11 Version 23H2/22H2用の更新プログラムKB5065431では、8月26日に公開されたKB5064080の内容に加え、UACプロンプトの問題の修正や、SMB監査機能の強化が行われています。
リリースノートは以下の通りです。
ハイライト
This update addresses security issues for your Windows operating system.
改良と修正
[App compatibility (known issue)] Fixed: Addresses an issue that caused non-admin users to receive unexpected User Account Control (UAC) prompts when MSI installers perform certain custom actions. These actions might include configuration or repair operations in the foreground or background, during the initial installation of an application.
This issue could prevent non-admin users from running apps that perform MSI repairs, including Office Professional Plus 2010 and multiple applications from Autodesk (including AutoCAD). This fix reduces the scope for requiring UAC prompts for MSI repairs and enables IT admins to disable UAC prompts for specific apps by adding them to an allowlist.
For more information, see Unexpected UAC prompts when running MSI repair operations after installing the August 2025 Windows security update.
[File server] This update enabled auditing SMB client compatibility for SMB Server signing as well as SMB Server EPA. This allows customers to assess their environment and identify any potential device or software incompatibility issues before deploying the hardening measures that are already supported by SMB Server. For detailed guidance, see CVE-2025-55234.
既知の不具合
更新プログラムには既知の不具合は存在しません。
更新プログラムはWindows Updateの他、Microsoft Update Catalog、Windows Server Update Services(WSUS)を利用してインストールすることができます。
