Should you update to KB5094126?

From Windows updates, in the HARD wiki · Updated
This article is about one Windows release. For the latest version, see Windows updates.

No: install KB5127648 instead. KB5094126 is a security update Microsoft released on 9 Jun 2026 for Windows PCs. It fixes 106 security flaws, 18 rated critical and 88 important by Microsoft.[1] None of them is known to be used in attacks.

It has since been replaced by KB5101650, released 14 Jul 2026, which includes all of its fixes. If you’re on an older version, install that instead.

Should you update?

No: install KB5127648 instead. KB5127648 came out on 13 Oct 2026 and includes every fix in KB5094126, so there’s no reason to stop at this one. Software Update offers the newest version your device can run.

Is KB5094126 still safe?

Not any more. The 6 updates since, up to KB5127648, fix 2,203 security flaws that KB5094126 doesn’t, and each became public the day its fix shipped. Installing it is safe: get it only from Start → Settings → Windows Update, never from a link in an email, text or pop-up.

What it fixes

Microsoft lists 106 security flaws, 18 rated critical and 88 important by Microsoft.[1] The 106 critical and important ones are:

FlawSeverityWhat Microsoft calls it
CVE-2025-10263CriticalARM: CVE-2025-10263 Completion of affected memory accesses might not be guaranteed by completion of a TLBI [kernel]
CVE-2026-33828CriticalWindows Device Health Attestation (DHA) Elevation of Privilege Vulnerability
CVE-2026-42985CriticalRemote Desktop Client Remote Code Execution Vulnerability
CVE-2026-42992CriticalRemote Desktop Client Remote Code Execution Vulnerability
CVE-2026-44799CriticalRemote Desktop Client Remote Code Execution Vulnerability
CVE-2026-44801CriticalRemote Desktop Client Remote Code Execution Vulnerability
CVE-2026-44803CriticalWindows Graphics Component Remote Code Execution Vulnerability
CVE-2026-44810CriticalMicrosoft Cryptographic Services Elevation of Privilege Vulnerability
CVE-2026-44812CriticalWindows Graphics Component Remote Code Execution Vulnerability
CVE-2026-44815CriticalDHCP Client Service Remote Code Execution Vulnerability
CVE-2026-45607CriticalWindows Hyper-V Remote Code Execution Vulnerability
CVE-2026-45641CriticalWindows Hyper-V Remote Code Execution Vulnerability
CVE-2026-45657CriticalWindows Kernel Remote Code Execution Vulnerability
CVE-2026-47289CriticalRemote Desktop Client Remote Code Execution Vulnerability
CVE-2026-47291CriticalHTTP.sys Remote Code Execution Vulnerability
CVE-2026-47652CriticalWindows Hyper-V Remote Code Execution Vulnerability
CVE-2026-48563CriticalRemote Desktop Client Remote Code Execution Vulnerability
CVE-2026-48574CriticalWindows Media Remote Code Execution Vulnerability
CVE-2026-8863ImportantUEFI Secure Boot Security Feature Bypass Vulnerability
CVE-2026-34335ImportantWindows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
CVE-2026-40404ImportantWindows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability
CVE-2026-40409ImportantWindows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability
CVE-2026-41092ImportantMicrosoft Kinect Elevation of Privilege Vulnerability
CVE-2026-41108ImportantWindows DNS Client Elevation of Privilege Vulnerability
CVE-2026-42828ImportantWindows Projected File System Elevation of Privilege Vulnerability
CVE-2026-42829ImportantWindows Administrator Protection Secure Feature Bypass Vulnerability
CVE-2026-42836ImportantWindows Function Discovery Service (fdwsd.dll) Elevation of Privilege Vulnerability
CVE-2026-42837ImportantWindows Projected File System Elevation of Privilege Vulnerability
CVE-2026-42903ImportantWindows Kerberos Denial of Service Vulnerability
CVE-2026-42904ImportantWindows TCP/IP Elevation of Privilege Vulnerability
and 76 more

How to update, and how long it takes

Usually 15 to 60 minutes in all, with one or two restarts. You can keep working while it downloads.

  1. Save your work first.Windows restarts to finish the update, once or twice.
  2. Open Start → Settings → Windows Update.Select Check for updates. Windows downloads the month’s cumulative update; it includes every earlier fix.
  3. Restart when it asks.Select Restart now, or schedule it for tonight. Until it restarts, the fixes aren’t in place.
  4. Leave automatic updates on.In the same place, under Advanced options, turn on “Get me up to date” so restarts don’t wait for days.

To check it worked: Press Windows key + R, type winver and press Enter: it shows the OS build. It should say 26100.8875 or 26200.8875 or later.

Older devices

The same day, Microsoft released KB5095051 (118 security flaws), KB5093998 (102 security flaws) and KB5094127 (93 security flaws) for devices that stay on an older version. Each fixes the same holes where they apply.

Before and after

  • After: KB5101650, 14 Jul 2026, 373 security flaws
  • Windows updates, every release and the latest version
  • Updates, the latest version of everything HARD tracks

References

  1. ^ Microsoft. “KB5094126”, 9 Jun 2026.