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Patch intelligence record

Windows 11 25H2 (Build 26200.9550)

ProductWindows 11 Version25H2 Release dateSep 22, 2026 File size
Evidence summary: Negative 11 user reports found

Community consensus not established — 11 user reports, evidence strength Low-Medium. This is a verified report sample, not live consensus telemetry.

Last evidence checked: Oct 6, 2026

AUXSAYS verdict WAIT

Current reports mention update/install failure, bsod / stop error, and display regression. This page covers one cumulative update, not the whole 25H2 servicing train; reports about a later update are counted on that update's own page.

Recommendations

  • Pause updates if this machine is doing deadline-sensitive or production work.
  • Check Microsoft's known-issue and safeguard-hold list for this KB before installing.
  • Keep the uninstall path in mind: a cumulative update can be removed from Settings > Windows Update > Update history for a limited window after installation.

Current reports mention update/install failure in windows update, bsod / stop error in system stability, display regression in display / graphics.

Community monitoring MONITORING ACTIVE
Accepted reports
11
Latest evidence run
Oct 6, 2026
Healthy sources
2 fresh (success / no reports) · need 2
  • Microsoft Q&A (search) Completed last checked Oct 6, 2026
  • techcommunity windows sitemap Completed last checked Oct 6, 2026

Monitoring reflects community-evidence collection health for this exact release — an absence of reports is not a safety guarantee, and this is separate from the AUXSAYS verdict.

Vendor Known Issues — 4 active vendor-known issues

4 active 6 resolved

Official vendor Release Health status. Not counted as community reports. Official source ↗

Official Patch Notes — vendor release notes captured from the official source

Windows 11 25H2 cumulative update, OS build 26200.9550 (KB5124010). Released 2026-09-22 on the General Availability Channel. Update type 2026-09 D. This is the official Microsoft Windows release-health entry (learn.microsoft.com/windows/release-health). Known-issue and safeguard-hold details are published on the per-version Windows release-health status page. Microsoft Release Health status (official) for Windows 11.

Windows 11 in these notes: .

Windows 11 25H2 cumulative update, OS build 26200.9550 (KB5124010). Released 2026-09-22 on the General Availability Channel. Update type 2026-09 D. This is the official Microsoft Windows release-health entry (learn.microsoft.com/windows/release-health). Known-issue and safeguard-hold details are published on the per-version Windows release-health status page.

Microsoft Release Health status (official) for Windows 11 25H2: 4 active known issue(s), 6 resolved, 0 safeguard hold(s). Source: official Microsoft Windows release-health status page. This is vendor-published operational status, not user reports.

  • Resolved: Incorrect notifications that “Microsoft Defender Antivirus is turned off” Microsoft Defender Antivirus remains active and functioning correctly despite notifications following the latest update. — status Resolved; originating N/A; last updated 2026-09-30 16:42 PT.
  • Active: Devices might experience a black screen or desktop loading issues after sign-in Microsoft has received reports of this issue occurring in some virtual desktop environments. — status Mitigated; originating OS Build 26200.9278 KB5120998; last updated 2026-09-29 10:12 PT.
  • Active: Domain-joined devices might lose their secure trust relationship with the domain Some Credential Guard protected machine accounts might be unable to sign in interactively will valid domain credentials. — status Mitigated; originating OS Build 26200.9445 KB5124008; last updated 2026-09-29 10:12 PT.
  • Active: USB audio devices might fail to start or produce no sound Some USB Audio Class 1.0 devices display Code 10 or fail in multichannel audio modes after installing the Sept. 8 update — status Mitigated; originating OS Build 26200.9445 KB5124008; last updated 2026-09-29 10:12 PT.
  • Resolved: Remote Desktop Services might stop responding after Sept. 2026 security update Some Windows devices with Remote Desktop enabled might experience Remote Desktop Services (RDS) instability. — status Resolved KB5129195; originating OS Build 26200.9445 KB5124008; last updated 2026-09-17 19:22 PT; resolved by KB5129195.
  • Resolved: Host folder shares might be unavailable in Hyper-V-based Linux VMs Plan9 host folder shares might not appear in the guest environment after installing the September 2026 security update. — status Resolved KB5129195; originating OS Build 26200.9445 KB5124008; last updated 2026-09-14 13:30 PT; resolved by KB5129195.
  • …and 4 more known issue(s) on the official status page.
Technical Details
Released
Sep 22, 2026
File size
Official source checked
Oct 6, 2026
Official notes checked
Oct 6, 2026
Checksum

Use these hashes to verify downloaded installers match the files published with the official release.

User Reports / Sources (11)

User report sources used for the current read.

Official sources