Microsoft has fixed a known issue that resulted in connection issues with Always On VPN after installing the Windows 11 September 2026 security updates.
The Always On VPN The remote access solution replaces legacy DirectAccess technology and works with domain-joined, non-domain-joined, and Microsoft Entra ID-joined Windows 10, Windows 11, and Windows Server devices.
Always On VPN runs in the background and automatically creates a secure tunnel back to the corporate network when a device connects to the Internet.
As Microsoft first confirmed in a service alert sent to IT administrators in late September, on current systems running Windows 11 24H2 and later, the bug triggered Always On VPN errors when the first connection fails (e.g. when using automatic protocol selection with IKEv2 and SSTP).
On Tuesday, the company released cumulative updates KB5127648 and KB5127646, which address this known issue on all affected systems.
“When automatic protocol selection or protocol fallback was configured, affected VPN connections could become stuck in connection state or fail to connect after an initial connection attempt failed.” it said. “In some cases, subsequent connection attempts may display the error “The specified port is already in use.”
Microsoft has also provided a temporary solution for customers who are unable to immediately install the October 2026 Patch Tuesday Update. This requires them to select one of two VPN tunnel protocols to work around the issue.
“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,” Microsoft said. “Organizations should select the protocol based on their environmental, security and deployment needs.”
Emergency updates were released last month to fix Remote Desktop Services bugs. Problems with Hyper-Vand USB audio issues affecting personal and business Windows users, also triggered by the September 2026 updates.
It was also confirmed this week that non-admin users may have issues connecting to devices via Remote Desktop after installing recent Windows updates when the Admin Protection security feature is enabled.
