Microsoft fixes Windows 11 bug from October 2026 update KB5127648 that disabled Smart App Control and blocked re-enabling it
Matéria consolidada. Reúne 2 matérias que o Tifon tinha publicado separadamente sobre a mesma história. A IA reescreveu o relatório com o que as 2 fontes trouxeram em 03/11/2026 00:10; os links antigos trazem para cá.
Fontes: bleepingcomputer.com ↗ zdnet.com ↗
Microsoft has fixed a known issue in Windows 11 where the October 13, 2026 Patch Tuesday update (KB5127648) left Smart App Control switched off and unable to be turned back on, with the On option grayed out (zdnet.com, bleepingcomputer.com). The fix shipped in updates released October 28, 2026 and later, including the KB5127936 preview update (bleepingcomputer.com). Devices that already had the feature enabled were not affected and stayed protected (bleepingcomputer.com). Neither source reports exploitation, attacks or a CVE, but affected endpoints lacked a layer of protection against unknown malware until remediated (zdnet.com). The earlier report (zdnet.com, October 20) said Microsoft was still working on a fix and offered only a workaround; the later report (bleepingcomputer.com, November 2) confirms the fix is available.
Detalhes técnicos
- Affected component: Smart App Control in Windows 11 after KB5127648 (zdnet.com). Affected builds are 24H2 and later, where the feature had been turned off before the update (bleepingcomputer.com).
- Detection: in Settings > Privacy & security > Windows Security > App & browser control > Smart App Control settings, the bug is present if the setting is Off and the On option is grayed out (zdnet.com).
- Smart App Control relies on code integrity and app intelligence services, and works alongside SmartScreen and Microsoft Defender (bleepingcomputer.com).
- KB5127936 also fixes Remote Desktop failures when "Administrator protection" is enabled, and Always On VPN issues caused by the September 2026 cumulative updates (bleepingcomputer.com).
- No CVE, exploitation or threat actor activity is reported (zdnet.com).
Remediação
- Install the latest security update, or the KB5127936 preview update (released October 28, 2026 or later) (bleepingcomputer.com).
- Temporary registry workaround: from an elevated Command Prompt, add the DWORD values 2883193997 and 2850574478 (each set to 1) under
HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides, then reboot and re-enable Smart App Control (zdnet.com, bleepingcomputer.com). - Alternative for admins: install the KB5074105 Feature Preview Group Policies (261015_19222 and 261015_19221), set them to Enabled and restart the device (bleepingcomputer.com).
Relatos divergentes
- Fix status: zdnet.com (October 20) said Microsoft was working on a fix for a future release; bleepingcomputer.com (November 2, more recent) says the fix has shipped in updates from October 28, 2026. The later report is authoritative.
- Scope: zdnet.com describes the feature as turned Off after the update; bleepingcomputer.com specifies it affected devices where the feature had been off beforehand, while devices with it already enabled stayed protected. The latter is more detailed and more recent.
- Versions: bleepingcomputer.com cites 24H2 and later but also lists 25H2 and 26H2 in the workaround; zdnet.com gives no version detail.
Linha do tempo
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Microsoft fixes Smart App Control activation bug caused by October 2026 Windows 11 update KB5127648
ler a análise desta fonte ocultar
Microsoft has resolved a known issue in which some Windows 11 devices could not turn on Smart App Control after installing the October 2026 security update KB5127648. On affected devices running 24H2 and later, the option was grayed out in the Windows Security app. Devices that already had the feature enabled were not affected and stayed protected. The fix shipped in updates released October 28, 2026 and later, including the KB5127936 preview update. Microsoft also published a registry and Group Policy workaround for admins who do not want to deploy the preview update.
Technical Details
- Affected: Windows 11 24H2 and later (the article also lists 25H2 and 26H2 in the workaround) where Smart App Control had been turned off before the update.
- Smart App Control relies on code integrity and app intelligence services, and works alongside SmartScreen and Microsoft Defender.
- KB5127936 also fixes Remote Desktop failures when "Administrator protection" is enabled, and Always On VPN issues caused by the September 2026 cumulative updates.
Remediation
- Install the latest security update, or the KB5127936 preview update (released October 28, 2026 or later).
- Temporary workaround: from an elevated Command Prompt, add the DWORD values 2883193997 and 2850574478 (each set to 1) under
HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides, then restart. - Alternatively, install the KB5074105 Feature Preview Group Policies (261015_19222 and 261015_19221), set them to Enabled and restart the device.
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Microsoft's October 2026 Windows 11 Patch Tuesday update bug disables Smart App Control and blocks re-enabling it
ler a análise desta fonte ocultar
The Windows 11 Patch Tuesday update released on October 13 contains a bug that turns off Smart App Control, a feature introduced in 2022 that blocks potentially malicious or suspicious apps and files. Affected systems show the feature as Off with the On option grayed out, so users cannot re-enable it. Microsoft says it is working on a fix for a future release and has published a temporary workaround. The article does not report any exploitation or attacks, but affected endpoints lose a layer of protection against unknown malware until remediated.
Technical Details
- Affected component: Smart App Control in Windows 11, after the October 13, 2026 Patch Tuesday update.
- Detection: in Settings > Privacy & security > Windows Security > App & browser control > Smart App Control settings, the bug is present if the setting is Off and the On option is grayed out.
- No CVE, exploitation or threat actor activity is reported.
Remediation
- Apply the Microsoft-provided workaround: from an elevated command prompt, add two DWORD values (2883193997 and 2850574478, each set to 1) under
HKLM\SYSTEM\CurrentControlSet\Policies\Microsoft\FeatureManagement\Overrides, then reboot and re-enable Smart App Control. - Install the permanent fix once Microsoft releases it.