# Windows security update can prevent Smart App Control activation

_Published Friday, October 16, 2026 at 5:12 AM EDT · Security · Latest · Tier 2 — Notable_

![Windows security update can prevent Smart App Control activation — Primary](https://www.bleepstatic.com/content/hl-images/2026/04/01/Windows_11.jpg)

Microsoft says the KB5127648 Windows 11 security update can prevent some users from turning on Smart App Control. On affected devices running version 24H2 and later, the control can appear grayed out after the update if it was previously turned off.

Smart App Control uses Microsoft's app intelligence and code integrity features to block potentially harmful apps or binaries alongside Defender and SmartScreen. Microsoft has provided registry and Group Policy workarounds for administrators managing enterprise devices, but a fix is not yet available. Devices where Smart App Control is already enabled remain protected.

## Sources

- [BleepingComputer](https://www.bleepingcomputer.com/news/microsoft/kb5127648-windows-security-update-may-break-smart-app-control/)

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Canonical: https://techandbusiness.org/newswire/_uV0sPWTrP735wlMjhTezw
Published: 2026-10-16T09:12:25.520Z
Story chronology: 2026-10-16T08:44:22.000Z
Retrieved: 2026-10-16T11:24:39.234Z
Publisher: Tech & Business (techandbusiness.org)