This article is updated whenever Microsoft releases a Windows 11 Emergency update to fix issues with Windows 11 B release.
This article provides more details on any Windows 11 Emergency update(also known by the name out of band updates), which may be released bt Microsoft to fix a critical issue after the latest monthly updates.
About Windows 11 Emergency update
When Windows users encounter an issue with updates, the fix is usually delivered via Out of band updates. Unlike the predictable “Patch Tuesday” schedule, a Windows 11 emergency update is deployed only when a system-breaking bug simply cannot wait another month for a fix. It was particularly seen with Windows 11 January 2026 updates, where Microsoft had to ship two out of band updates to clean up the mess by the B release.
Latest Out-of-Band updates for Windows by Microsoft
The OOB releases listed below occurred after January 2026.
September 14, 2026—KB5129195 (OS Builds 26200.9457 and 26100.9457) Out-of-band
Microsoft has taken care of the following widespread issues in this update, after the September update:
- [Security] This update includes protections documented in CVE-2026-62721, which refers to a Windows User-Mode Power Service (UMPS) Elevation of Privilege vulnerability.
- [Remote Desktop Services (known issue)] Fixed: This update addresses an issue affecting Remote Desktop Services (RDS) after installing the September 2026 Windows security update (KB5122880). In affected environments, RDS might become unstable, causing RDP connection and sign-in failures or servers to become unresponsive during Remote Desktop configuration. Related tools, including Microsoft Management Console (MMC), RDS Licensing Diagnoser, File Explorer, and the Windows Update page, might also stop responding.
- [Hyper-V (known issue)] Fixed: Some applications that use HCS-managed virtual machines experienced issues when sharing host folder with Linux VMs using Plan9. Folders shared from the Windows host using Plan9 did not appear or could not be accessed in the guest environment.
- [8-channel or 3D audio modes] Fixed: Some USB Audio Class 1.0 devices functioning as expected in standard stereo configurations failed when using multichannel audio features, including 8-channel or 3D audio modes. (Note: There are other audio symptoms not resolved in this OOB update. See the “Known issues in this update” section for more information.)
January 24, 2026—KB5078127 (OS Builds 26200.7628 and 26100.7628) Out-of-band
With this update, Microsoft addressed the following issues after releasing the previous emergency Patch, which addressed only one issue.
Fixed: After installing the Windows update released on and after January 13, 2026, some applications became unresponsive or encountered unexpected errors when opening files from or saving files to cloud-based storage, such as OneDrive or Dropbox. In certain Outlook configurations that store PST files on OneDrive, Outlook may hang and fail to reopen unless the process is terminated or the system is restarted. Users may also see missing sent Items or previously downloaded emails being re‑downloaded.
January 17, 2026—KB5077744 (OS Builds 26200.7627 and 26100.7627) Out-of-band – Microsoft Support
Via the support document , this update fixed the following issues from the January 2026 B Release.
[Remote Desktop] Fixed: After installing the January 2026 Windows security update (KB5074109), some users experienced sign-in failures during Remote Desktop connections. This issue affected authentication steps for different Remote Desktop applications on Windows such as the Windows App.
More updates would be added, as Microsoft releases them.
A small note about Windows update terminology
Windows 11 has a monthly release cadence, with the main update released on the second Tuesday of each month, known as the “B release”. Additionally, a preview update of the next month is shipped in the 3rd or 4th week of the month, called as “C release”, so that they can identify issues. The subject of this article, i.e., Out-of-Band updates, is released whenever they are needed, depending on the severity of the issue.