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The September 2025 Windows security update is now available
MC1150558 · build prod-20251231-200323
Category
stayInformed
Severity
normal
Major change
True
Last modified
2025-09-09 17:07:06
Summary source
Azure OpenAI (gpt-4.1)
Action by (Graph)
Action by (AI)
Services
Windows
Tags
Admin impact
Master tags
Security
Roadmap IDs

One-line summary

September 2025 security update for Windows 10/11 and Windows Server adds quality, security, and SMB auditing improvements; prompt installation is recommended.

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Details

Body (from Message Center)

The September 2025 security update is now available for all supported versions of Windows. We recommend that you install these updates promptly. For more information about the contents of this update, see the release notes, which are easily accessible from the Windows 11 and Windows 10 update history pages. To learn more about the different types of monthly quality updates, see Windows monthly updates explained.
  
Highlights for the Windows 11, version 24H2 update: 
  • This security update includes improvements that were a part of update KB5064081 (released August 29, 2025).
  • This update makes quality improvements to the servicing stack, which is the component that installs Windows updates.
  • This update addresses an issue that caused non-admin users to receive unexpected User Account Control (UAC) prompts when MSI installers perform certain custom actions.
  • This update enables auditing Server Message Block (SMB) client compatibility for SMB Server signing as well as SMB Server Extended Protection for Authentication (EPA). This allows customers to assess their environment before deploying the hardening measures that are already supported by SMB Server. 
  • This update addresses an issue that affects audio in apps using the Network Device Interface (NDI). 

Short on time? Watch our Windows 11 release notes video for this month's tips.

Note: To address an issue with Windows Powershell PSDirect connections, Microsoft recommends applying the September 2025 security update for Windows PowerShell in hotpatched devices.
  • KB5066360 - Windows Server 2025 Datacenter: Azure Edition
  • KB5066360 - Windows 11 Enterprise LTSC 2024
  • KB5066359 - Windows Server 2022 Datacenter: Azure Edition

For instructions on how to install this update, see the KB for your operating system listed below: 
  • Windows 11, version 24H2: KB5065426
  • Windows 11, versions 23H2 and 22H2: KB5065431
  • Windows 11 Enterprise LTSC 2024: Hotpatch KB5065474
  • Windows 10, versions 22H2 and 21H2: KB5065429
  • Windows 10 Enterprise LTSC 2019 and Windows Server 2019: KB5065428
  • Windows 10 LTSB 2016 and Windows Server 2016: KB5065427
  • Windows 10 LTSB 2015: KB5065430
  • Windows Server 2025: KB5065426
  • Windows Server 2025 Datacenter: Azure Edition: Hotpatch KB5065474
  • Windows Server 2022: KB5065432
  • Windows Server 2022 Datacenter: Azure Edition: Hotpatch KB5065306
  • Windows Server 2012 R2: Monthly Rollup: KB5065507
  • Windows Server 2012: Monthly Rollup: KB5065509
  • Windows Server 2008 R2 Service Pack 1: Monthly Rollup: KB5065468 / Security Only: KB5065510
  • Windows Server 2008 SP2: Monthly Rollup: KB5065508 / Security Only: KB5065511

Raw JSON (for debugging)

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{
  "snapshot_item": {
    "action_required_by": null,
    "ai_action_required_by": null,
    "ai_actions": [
      "Install September 2025 security update on all supported Windows and Windows Server devices",
      "Review release notes for update details",
      "Apply Windows PowerShell update on hotpatched devices if needed"
    ],
    "ai_master_tags": [
      "Security"
    ],
    "ai_model": "gpt-4.1",
    "ai_summary": "September 2025 security update for Windows 10/11 and Windows Server adds quality, security, and SMB auditing improvements; prompt installation is recommended.",
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    "details_map": {},
    "id": "MC1150558",
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    "last_modified": "2025-09-09T17:07:06Z",
    "ms_products": [
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    "roadmap_ids": [],
    "services": [
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    "severity": "normal",
    "tags": [
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    "title": "The September 2025 Windows security update is now available\t"
  }
}