Microsoft Fixes Always On VPN Failures Caused by September Windows Updates
Summary
Microsoft says the October 2026 KB5127936 preview update fixes Always On VPN failures triggered by September Windows 11 security updates. Admins can temporarily switch from automatic protocol selection to SSTP or IKEv2.
Key points
- The September 2026 Windows 11 security updates caused Always On VPN failures when automatic protocol selection used IKEv2 and SSTP.
- Affected connections could remain stuck at “Connecting” or fail; later attempts could report that the specified port was already in use.
- Microsoft says the KB5127936 preview update fixes the VPN issue.
- As a workaround, administrators can configure affected VPN profiles to use only SSTP or only IKEv2, based on their environment and requirements.
- The October 2026 preview update also fixes a Remote Desktop connection issue for non-admin users when Administrator protection is enabled.
Article Details
- Event Type
- Windows 11 update-related Always On VPN connectivity issue and subsequent fix
- Impact
- September 2026 security updates caused affected Always On VPN connections using automatic protocol selection or fallback with IKEv2 and SSTP to remain stuck in Connecting or fail, sometimes displaying “The specified port is already in use.” Microsoft confirmed the issue was fixed for users who installed the October preview update KB5127936. As a temporary workaround, administrators can configure the VPN profile to use SSTP only or IKEv2 only. The same preview update also fixes a Remote Desktop connection issue affecting non-admin users when Administrator protection is enabled.
Vendors
Products
Always On VPNMicrosoft has resolved Always On VPN connection failures triggered after installing the September 2026 Windows 11 security updates.Remote Desktoppreview update also fixes a known issue preventing non-admin users from connecting to devices via Remote Desktop when the "Administrator protection" security feature is enabled after installing the September 2026Windows 11Microsoft has resolved Always On VPN connection failures triggered after installing the September 2026 Windows 11 security updates.