Microsoft released February 2026 Patch Tuesday updates for Windows 11 25H2, 24H2, and 23H2, addressing 58 security flaws including six actively exploited zero-day vulnerabilities. The cumulative updates KB5077181 and KB5075941 bundle security patches with quality improvements for all supported Windows 11 versions.
Windows 11 24H2 and 25H2 systems receive KB5077181, bumping builds to 26100.7840 and 26200.7840 respectively. Windows 11 23H2 systems get KB5075941, raising the OS to Build 22631.6649. Both updates include February's security patches and incorporate non-security improvements from January's optional preview releases.
The February 2026 Patch Tuesday addresses five critical vulnerabilities, three elevation of privilege flaws, and two information disclosure issues.
Among the six zero-day vulnerabilities, one actively exploited Windows security feature bypass allows attackers to bypass Mark of the Web security warnings by opening specially crafted links or shortcut files. Another MSHTML security feature bypass flaw enables unauthorized attackers to bypass security features over networks.
Microsoft also warns about Secure Boot certificate expirations starting in June 2026. The 2011-era certificates that verify bootloaders through UEFI Secure Boot will expire, potentially locking devices out of future security patches if not updated.
Windows quality updates now include targeting data to determine which devices are ready to receive new Secure Boot certificates, with PCs manufactured since 2024 likely already having the updated 2023-era certificates preinstalled.
For Windows 11 23H2, KB5075941 fixes a widely discussed shutdown issue where some PCs running Virtual Secure Mode could restart instead of shutting down or entering hibernation after security updates released on or after January 13, 2026. The update also replaces 2011-signed bootmgfw.efi with 2023-signed versions on devices with Windows UEFI CA 2023 certificates.
Separately, Microsoft confirmed Windows 11 version 26H1 will ship exclusively on new Snapdragon X2 devices this spring, not as an update for existing PCs.
The company described 26H1 as a "targeted release that supports some of the new device innovations coming in 2026" rather than a broad feature update.
Microsoft reports no known issues with either KB5077181 or KB5075941 at publication time, with the updates available through Windows Update and the Microsoft Update Catalog for offline installation.
