Microsoft fixes Windows 11 Always On VPN failures from September 2026 updates in KB5127936 preview update
Matéria consolidada. Reúne 2 matérias que o Tifon tinha publicado separadamente sobre a mesma história. A IA reescreveu o relatório com o que a fonte trouxe em 31/10/2026 00:05; os links antigos trazem para cá.
Fontes: bleepingcomputer.com ×2 ↗
Microsoft has fixed a known issue in which Always On VPN connections failed on Windows 11 after the September 2026 security updates. The fix is in the KB5127936 preview update (bleepingcomputer.com, Oct 30, 2026). Microsoft had wrongly marked the issue resolved in the October 2026 Patch Tuesday cumulative updates. It reverted the status to Mitigated and promised a permanent fix "in the coming weeks" (bleepingcomputer.com, Oct 21, 2026). The bug affected profiles using automatic protocol selection or fallback between IKEv2 and SSTP. Connections stayed stuck in a Connecting state or failed with the error "The specified port is already in use." This is a reliability and availability problem, not a security vulnerability, and no exploitation is reported. It still disrupted remote access for corporate fleets.
Detalhes técnicos
- Affected systems: Windows 11 24H2 and later with the September 2026 security updates installed. The trigger is a failed initial Always On VPN connection attempt, for example with automatic protocol selection across IKEv2 and SSTP (bleepingcomputer.com).
- Symptoms: connections hang in Connecting, or fail after the first failed attempt. Later attempts may show "The specified port is already in use." When automatic selection or fallback was configured, a failed initial attempt could leave the tunnel unable to reconnect (bleepingcomputer.com).
- Status history: Microsoft first acknowledged the issue in a service alert to IT administrators in late September 2026. The alert was wrongly set to Resolved on October 13, 2026 and later returned to Mitigated (bleepingcomputer.com).
- Background: Always On VPN replaces legacy DirectAccess. It supports domain-joined, non-domain-joined and Microsoft Entra ID-joined devices on Windows 10, Windows 11 and Windows Server (bleepingcomputer.com).
- Same preview update: KB5127936 also fixes a separate issue that stopped non-admin users from connecting via Remote Desktop when the Administrator protection feature is enabled (bleepingcomputer.com).
- Other September 2026 update problems: Hyper-V issues, Remote Desktop Services failures, USB audio problems (fixed with emergency out-of-band updates), domain credential login failures (temporary workaround issued) and a broken File History backup feature (fix in progress) (bleepingcomputer.com, Oct 21).
Remediação
- Install the KB5127936 October 2026 preview update, or wait for the next Patch Tuesday cumulative update (bleepingcomputer.com).
- Workaround until patched: change the Always On VPN profile from automatic protocol selection to a single protocol, either SSTP only or IKEv2 only. Choose it according to environment, security and deployment requirements (bleepingcomputer.com).
Relatos divergentes
- Fix status: the Oct 21 article (bleepingcomputer.com) says the issue was only mitigated, that the Resolved mark was a mistake, and that the permanent fix would come in the coming weeks. The Oct 30 article (bleepingcomputer.com) reports the fix is now delivered in KB5127936. The Oct 30 report is more recent and supersedes the earlier one.
Linha do tempo
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Microsoft fixes Always On VPN connection failures caused by September 2026 Windows 11 updates
ler a análise desta fonte ocultar
Microsoft has fixed a known issue in which Always On VPN connections failed on Windows 11 systems after installing the September 2026 security updates. The bug affected profiles using automatic protocol selection or protocol fallback with IKEv2 and SSTP, leaving connections stuck in a Connecting state or returning the error 'The specified port is already in use.' Microsoft first acknowledged the issue in a service alert to IT administrators in late September 2026 and had previously (and mistakenly) marked it resolved in the October 2026 cumulative updates. The fix is now delivered in the KB5127936 preview update. This is a reliability/availability issue rather than a security vulnerability, but it affects remote access for corporate fleets.
Technical Details
Always On VPN replaces legacy DirectAccess and supports domain-joined, non-domain-joined and Microsoft Entra ID-joined devices on Windows 10, Windows 11 and Windows Server. When automatic protocol selection or fallback was configured, a failed initial connection attempt could leave the tunnel unable to reconnect. The same KB5127936 preview update also resolves a separate issue preventing non-admin users from connecting via Remote Desktop when the Administrator protection feature is enabled.
Remediation
Install the KB5127936 October 2026 preview update, or wait for the next Patch Tuesday cumulative update. As a workaround, administrators can change the Always On VPN profile from automatic protocol selection to a single protocol — SSTP only or IKEv2 only — based on environment and security requirements.
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Microsoft reverts fix status for Always On VPN failures on Windows 11 after October 2026 updates; workaround issued
ler a análise desta fonte ocultar
Microsoft says it mistakenly marked a bug affecting Always On VPN connections as resolved in the October 2026 Patch Tuesday cumulative updates for Windows 11. The status was reverted to Mitigated, and a permanent fix is planned for an update "in the coming weeks". The issue first appeared after the September 2026 security updates on Windows 11 24H2 and later. It is a reliability problem, not a security vulnerability, and the article reports no exploitation.
Technical Details
- Affected: systems running Windows 11 24H2 and later with the September 2026 security updates, when the initial Always On VPN connection attempt fails (e.g. automatic protocol selection with IKEv2 and SSTP).
- Symptoms: connections stay stuck in a Connecting state or fail after an initial failed attempt. Later attempts may show the error "The specified port is already in use."
- The service alert was wrongly set to Resolved on October 13, 2026 and returned to Mitigated in a Tuesday update.
- The September cumulative updates were also linked to other problems: Hyper-V issues, Remote Desktop Services failures, USB audio problems (fixed with emergency out-of-band updates), domain credential login failures (temporary workaround issued), and a broken File History backup feature (fix in progress).
Remediation
- Change the Always On VPN profile from automatic protocol selection to a single protocol, either SSTP only or IKEv2 only.
- Choose the protocol according to the environment, security and deployment requirements.
- Watch for the upcoming update that Microsoft says will contain the permanent fix.