Microsoft released its October 2026 monthly security update for Windows 11 on October 13, according to BigGo ファイナンス. The cumulative package, identified as KB5127648, addresses versions 24H2, 25H2, and 26H2, corresponding to builds 26100.9711, 26200.9711, and 26300.9711. Version 26H1 receives a separate package, KB5127646.
Among the changes is a fix for mouse input stutter that some users experienced in certain games. BigGo ファイナンス reports that this marks the first time the gaming-related correction has been made broadly available, as it was not included in the optional preview build distributed on September 22.
The update also introduces the ability to reassign the Copilot key. Users can find the option under Settings > Bluetooth & devices > Keyboard, where the key can be configured to act as either the right Ctrl key or the context menu key. Microsoft cautions that selecting right Ctrl may interfere with shortcuts such as "Right Ctrl + Win," and suggests the left Ctrl key as a safer alternative for users who rely on those combinations. The feature is being rolled out gradually.
Why it matters
The October release carries unusual weight for two reasons. First, it fixes more than 1,400 CVEs, which Microsoft and independent security tracking organizations describe as the highest monthly total on record, though exact counts vary slightly between sources. The scope covers Windows, Office, Exchange Server, .NET, and Visual Studio, and includes multiple critical-severity flaws that allow remote code execution.
Second, two of the patched vulnerabilities stand out. CVE-2026-96951, a Windows Shell flaw that bypasses Mark of the Web protections, was already being exploited in the wild before the update shipped. Microsoft is urging immediate patching. The second, CVE-2026-108398, affects .NET Framework; it had been publicly disclosed, but no active exploitation has been confirmed.
The same date also marks the end of support for Windows 11 24H2 Home and Pro editions, making KB5127648 the final security update those versions will receive. Users on those editions need to move to 25H2 or 26H2 to keep getting patches. Enterprise and Education editions of 24H2 remain supported until October 12, 2027. Windows 11 23H2 receives KB5126653 as part of the same release cycle.
Beyond gaming: a broad set of fixes
The gaming entry in the release notes is a single line stating that a problem causing mouse input stutter in specific titles has been resolved. BigGo ファイナンス notes that Microsoft has not disclosed the root cause, the affected games, or the hardware configurations involved, leaving details such as DPI settings, polling rates, and graphics APIs unconfirmed.
Other corrections in the package cover a range of everyday problems. The Explorer preview pane once again displays downloaded files properly, including PDFs. Microsoft also fixed a failure of Windows Hello fingerprint sign-in after a cold boot, crashes tied to AC-3 audio, Always On VPN connection issues, and printing failures involving RAW or Generic Text Only drivers.
Two additional items round out the release. A Manitoba time zone at UTC-05:00 was added ahead of the province's November 1 change, and an issue preventing some Storage Spaces and direct virtual disks from coming online was resolved.
What to watch
With a zero-day already under active exploitation and critical flaws spanning multiple Microsoft products, BigGo ファイナンス reports that administrators and individual users alike are being advised to apply the October updates promptly through Windows Update or their standard patch management workflows. The scale of this month's release is expected to put particular pressure on organizations managing mixed Windows environments, where timely deployment is essential.
