Microsoft has addressed a connectivity problem affecting Always On VPN deployments that emerged following the September 2026 Windows 11 security patches. The issue prevented remote access connections from establishing properly on systems running Windows 11 24H2 and later versions.
Always On VPN serves as the successor to the older DirectAccess remote access technology. It operates across domain-joined machines, non-domain-joined devices, and systems connected to Microsoft Entra ID, spanning Windows 10, Windows 11, and Windows Server platforms. The solution maintains a background connection that automatically initiates a secure tunnel to corporate networks whenever a device gains internet connectivity.
The problem manifested when automatic protocol selection was enabled and initial connection attempts failed—particularly when systems attempted to fall back between IKEv2 and SSTP protocols. Microsoft first notified IT administrators of the issue through a service alert in late September.
According to Microsoft's description of the bug, "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, 'The specified port is already in use.'" The company released cumulative updates KB5127648 and KB5127646 on Tuesday to resolve the issue across all impacted systems.
For organizations unable to immediately deploy the October 2026 Patch Tuesday updates, Microsoft provided a temporary workaround. "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 stated. "Organizations should select the protocol based on their environment, security, and deployment requirements."
The VPN connectivity problems represent one of several issues stemming from the September 2026 updates. Microsoft previously released emergency patches addressing Remote Desktop Services failures, Hyper-V complications, and USB audio malfunctions affecting both consumer and enterprise deployments. Additionally, the company recently identified a separate issue where non-administrator users encounter connection failures when accessing remote devices via Remote Desktop if the "Administrator protection" security feature is active.