Microsoft Fixes September VPN Update Issues
Microsoft has addressed a known issue that disrupted Always On VPN connections following the installation of September 2026 Windows 11 security updates.
Radwan AbdulhadiEditor and technology writer
Resolution for Always On VPN Issues
Microsoft has resolved a known issue that caused Always On VPN connection issues after installing the September 2026 Windows 11 security updates.
The [Always On VPN] remote access solution replaced the legacy DirectAccess technology and works with domain-joined, non-domain-joined, and Microsoft Entra ID–joined Windows 10, Windows 11, and Windows Server devices. It runs in the background and automatically establishes a secure tunnel back to the corporate network whenever a device connects to the internet.
Impact of the September 2026 Updates
As Microsoft first acknowledged [in a service alert sent to IT administrators] in late September, the bug triggered Always On VPN failures if the initial connection fails, such as when using automatic protocol selection with IKEv2 and SSTP, on up-to-date systems running Windows 11 24H2 and later.
When automatic protocol selection or protocol fallback was configured, affected VPN connections could remain stuck in a Connecting state or fail to connect after an initial connection attempt failed. In some cases, subsequent connection attempts could display the error stating that the specified port is already in use.
New Cumulative Updates and Temporary Fixes
To address this known issue on all affected systems, the company released the [KB5127648 and KB5127646 cumulative updates] on Tuesday.
In documentation regarding the update, [it said] that affected VPN connections could remain stuck or fail when automatic settings were utilized.
Microsoft also shared a temporary fix for customers who cannot immediately install the October 2026 Patch Tuesday update. This workaround requires administrators to choose one of two VPN tunneling protocols. IT administrators can mitigate this issue by changing the Always On VPN profile from automatic protocol selection to a single protocol, either SSTP only or IKEv2 only, depending on their environment and configuration. Organizations should select the protocol based on their specific deployment requirements.
Broader Update Complications
Last month, Microsoft [released emergency updates] to address multiple distinct bugs. These included fixes for [Remote Desktop Services failures], [Hyper-V issues], and [USB audio problems] affecting home and enterprise Windows users, all of which were triggered by the September 2026 updates.
Additionally, the company confirmed this week that non-admin users [may have issues connecting to devices via Remote Desktop] after installing recent Windows updates if the Administrator protection security feature is enabled.
Sources
- BleepingComputerMicrosoft fixes VPN issues caused by September Windows updates
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