New Update Windows 11 September 2026 Patch Tuesday (KB5124008, KB5122880)

[Gandalf_The_Grey]

Microsoft has released the September 2026 Patch Tuesday updates for Windows 11 25H2, 24H2. The 25H2 and 24H2 update is provided via KB5124008 (manual download link below), build 26100.9445 on 24H2, and build 26200.9445 on 25H2, after applying the updates. Windows 11 23H2 is available under KB5122880 (manual download link below), build 22631.7582.

The changelog for Windows 11 25H2, 24H2 is given below:

• [Security updates] This update provides security improvements.
• [Secure Boot] This update includes additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Certificate deployment via Windows updates continues across supported PCs and non-managed business devices in the coming months.
• [Mouse] Fixed: This update addresses an issue that prevented customized mouse cursor settings, including pointer style and color, from displaying correctly. Selected cursor options and colors now work as expected.
• [Personalization] Fixed: This update addresses an issue where desktop background and other personalization settings might not load correctly, causing the desktop background to appear black.
• [Teams and Outlook on Arm64 PCs] Fixed: This update addresses an issue that could cause Microsoft Teams and Microsoft Outlook to unexpectedly close on Arm64-based PCs.
• [Date and Time] This update adjusts Morocco Standard Time to reflect Morocco's transition to permanent UTC+00:00 effective September 20, 2026. This change ensures that the correct local time is displayed after the transition.
• [Remote Desktop Audio Redirection] This update addresses an issue affecting Remote Desktop audio redirection that could prevent audio from a remote session from playing on the local device in certain configurations.
• [OMA-DM Client Logging] This update improves diagnostic logging for the OMA-DM client, providing additional information to help troubleshoot device management server connection issues.

https://www.neowin.net/news/windows-11-kb5124008-kb5122880-september-2026-patch-tuesday-now-available-to-download/

 

[lokamoka820]

Microsoft Confirms September Windows 11 Updates Break Always On VPN Connections

Microsoft has confirmed that the security updates for Windows 11 which are scheduled for September 2026 may cause Always On VPN connections to fail, leaving the affected devices unable to access corporate networks.

The company mentioned the issue in a Windows release health service alert aimed at IT administrators and has put out a temporary workaround while a permanent solution is being developed.

Microsoft states that when the September update has been installed, affected systems experience problems when attempting to connect to an organisation's enterprise network via Always On VPN.

The connection might remain in a "Connecting" state or may cause repeated retry attempts which are unsuccessful. The error message "The specified port is already in use" may also occur on later attempts.

Microsoft Confirms September Windows 11 Updates Break Always On VPN Connections - gHacks Tech News

Microsoft says September 2026 Windows 11 updates can leave Always On VPN stuck and shares a workaround.

www.ghacks.net

 

[Brownie2019]

Microsoft has confirmed that the security updates for Windows 11 which are scheduled for September 2026 may cause Always On VPN connections to fail, leaving the affected devices unable to access corporate networks.

The company mentioned the issue in a Windows release health service alert aimed at IT administrators and has put out a temporary workaround while a permanent solution is being developed.

Microsoft states that when the September update has been installed, affected systems experience problems when attempting to connect to an organisation's enterprise network via Always On VPN.

The connection might remain in a "Connecting" state or may cause repeated retry attempts which are unsuccessful. The error message "The specified port is already in use" may also occur on later attempts.

Affected Windows 11 Versions and Updates​

Microsoft lists three Windows 11 releases as affected, each tied to a specific September cumulative update:

• Windows 11, version 26H1, after installing KB5124012
• Windows 11, version 25H2, after installing KB5124008
• Windows 11, version 24H2, after installing KB5124008

The programme relies on a single configuration option; according to Microsoft, the problem occurs when the VPN is configured to attempt another connection method if the first one fails, for example when automatic protocol selection is used with IKEv2 and SSTP.

Always On VPN is the remote access solution that Microsoft is presenting as a replacement for DirectAccess; it is compatible with domain-joined, non-domain-joined, and Microsoft Entra ID joined devices and automatically sets up a tunnel to the corporate network each time a device goes online. This alert does not apply to devices that are not using an Always On VPN profile.

How Administrators Can Work Around the Always On VPN Issue​

At the moment, there is no permanent solution available, so Microsoft advises that affected profiles be moved away from automatic protocol selection until one is released.

1. Open the Always On VPN profile configuration that is used by the affected Windows 11 devices.
2. Set the tunneling option to use a single protocol instead of having it automatically select the protocol.
3. Choose between SSTP alone and IKEv2 alone depending on the organization's environment, security needs, and deployment requirements.
4. Install the updated profile and make sure that the devices leave the 'Connecting' state and set up the tunnel.

The result is greater flexibility; when automatic selection is disabled, the device can't switch to the second protocol if the first one fails on a particular network, which is why Microsoft lets each organization decide which protocol to use rather than recommending a specific one.

The VPN issue is now part of an increasing number of problems associated with the September 2026 cumulative updates. Microsoft has already issued emergency updates to correct failures of Remote Desktop Services, problems with Hyper-V, and issues with USB audio.

The company has also provided a workaround for a bug that prevents some Windows 11 users from logging in with valid domain credentials, and is currently investigating a different issue that can cause the File History backup feature to stop working.

Microsoft has not stated when a permanent fix for the Always On VPN problem will be released or whether it will come in an out-of-band update or in a regular monthly update.

Microsoft Confirms September Windows 11 Updates Break Always On VPN Connections - gHacks Tech News

Microsoft says September 2026 Windows 11 updates can leave Always On VPN stuck and shares a workaround.

www.ghacks.net

 

[Brownie2019]

Microsoft has confirmed that some users may experience desktop loading issues, including black screens, after installing the August 2026 preview updates and subsequent updates.

However, the company says this mainly affects Azure Virtual Desktop (AVD) hosts using FSLogix (a software solution that speeds up user profile loading in virtual desktop environments).

Windows users affected by this known issue may experience multiple symptoms. The most common symptoms include a black screen after sign-in, so users can't access their desktop until they start the desktop session manually, and application event logs showing Windows Explorer crashes.

Until a permanent fix is available for those who installed KB5120996 (Windows 11 26H1), KB5120998 (Windows 11 24H2/25H2), and this month's Patch Tuesday updates (KB5124008 and KB5122880), Microsoft says users can temporarily work around the issue by manually launching Windows Explorer.

This can be done by opening Task Manager (Ctrl+Shift+Esc), selecting Run new task, entering explorer.exe, and clicking OK.

Microsoft has also mitigated this issue for enterprise customers via Known Issue Rollback (KIR), a Windows feature that reverses buggy updates delivered through Windows Update.

IT administrators can apply the mitigation on enterprise-managed devices by installing one of the following group policies:

• Windows 11, version 26H1: KB5124006 Known Issue Rollback
• Windows 11, version 25H2 and Windows 11, version 24H2: KB5124010 Known Issue Rollback

"You will need to install and configure the Group Policy for your version of Windows to resolve this issue. You will also need to restart your device(s) to apply the group policy setting," Microsoft said. "Note that this Group Policy will disable the change causing this issue until a resolution is released in a future Windows update.

Admins can find further guidance on deploying and configuring KIR group policies on Microsoft's support website.

Earlier this month, Microsoft also resolved known issues that wiped mouse and desktop settings on some Windows 11 systems that were also triggered after installing the KB5120998 August 2026 optional update.

Microsoft: Recent Windows updates cause desktop loading issues

Microsoft has confirmed that some users may experience desktop loading issues, including black screens, after installing the August 2026 preview updates and subsequent updates.

www.bleepingcomputer.com

 

[lokamoka820]

Microsoft Fixes File History Backup Failures Caused by September Windows Updates

Microsoft has fixed a known issue that stopped the File History backup feature from working on some Windows PCs after the September 2026 security updates were installed.

The fix ships in the optional KB5124010 and KB5124006 cumulative updates for Windows 11, according to Microsoft, and Windows 11 users who skip those optional updates will receive it with the October 13 Patch Tuesday release.

Microsoft first warned about the problem in a Saturday service alert on its Windows release health dashboard. On affected systems, File History stops creating or updating backups, and Event Viewer records application crash events that reference FileHistory.exe and KERNELBASE.dll.

Microsoft Fixes File History Backup Failures Caused by September Windows Updates - gHacks Tech News

Microsoft's optional KB5124010 and KB5124006 updates fix File History backups broken by September patches.

www.ghacks.net