Microsoft Windows Updates: MOTW Bypass Patch and Windows 11 Shutdown Regression
Microsoft issued security updates to remediate a Windows Remote Assistance protection-mechanism failure, CVE-2026-20824, that can allow attackers to bypass Mark of the Web (MOTW)—a key Windows control used to flag and apply additional restrictions to files originating from the internet. Reporting notes the issue is not “wormable” and requires local execution plus user interaction, but it can materially weaken common download-based defenses and be chained with other techniques to increase the likelihood of successful payload execution.
Separately, Microsoft released an out-of-band/emergency fix after a Patch Tuesday update introduced a Windows 11 23H2 regression where some systems configured with Secure Launch restart instead of shutting down (and may also fail to hibernate). A documented workaround for affected endpoints is to invoke shutdown via Command Prompt using:
shutdown /s /t 0
Other items in the set are not part of these Windows security/patch events: a PowerToys feature update, an iOS upgrade opinion piece, and a Windows 11 edition comparison.
Timeline
Jan 19, 2026
Microsoft discloses Windows 11 shutdown bug affecting Secure Launch devices
Microsoft said some Windows 11 23H2 PCs configured with Secure Launch could no longer shut down normally after installing KB5073455, instead restarting when users selected Shut down. The company said it was investigating, advised users to save work to avoid data loss, and provided a Command Prompt shutdown workaround while noting no workaround for a related hibernation issue.
Jan 13, 2026
Microsoft patches Windows Remote Assistance MOTW bypass flaw
Microsoft released security updates to fix CVE-2026-20824, a Windows Remote Assistance vulnerability that could bypass Mark of the Web protections on downloaded files. The flaw could aid social-engineering attack chains by reducing security warnings and weakening controls that rely on MOTW metadata.
Jan 13, 2026
Microsoft releases KB5073455 Patch Tuesday update for Windows 11 23H2
Microsoft issued the Windows 11 23H2 update KB5073455 as part of Patch Tuesday. After installation, some systems later experienced a shutdown-related regression tied to Secure Launch configurations.
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1 months ago
Microsoft Windows 11 Updates Trigger Boot Failures and Security-Driven Driver/Privilege Changes
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