Should you update to KB5099414?
No: install KB5126653 instead. KB5099414 is a security update Microsoft released on 14 Jul 2026 for Windows PCs. It fixes 18 security flaws, 1 rated critical and 17 important by Microsoft.[1] None of them is known to be used in attacks.
It has since been replaced by KB5120240, released 11 Aug 2026, which includes all of its fixes. If you’re on an older version, install that instead.
Should you update?
No: install KB5126653 instead. KB5126653 came out on 13 Oct 2026 and includes every fix in KB5099414, so there’s no reason to stop at this one. Software Update offers the newest version your device can run.
Is KB5099414 still safe?
Not any more. The 3 updates since, up to KB5126653, fix 1,736 security flaws that KB5099414 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 18 security flaws, 1 rated critical and 17 important by Microsoft.[1] The 18 critical and important ones are:
| Flaw | Severity | What Microsoft calls it |
|---|---|---|
CVE-2026-42982 | Critical | Windows Secure Kernel Mode Elevation of Privilege Vulnerability |
CVE-2026-33842 | Important | Windows File Explorer Information Disclosure Vulnerability |
CVE-2026-34328 | Important | Windows Audio Service Information Disclosure Vulnerability |
CVE-2026-34346 | Important | Windows Ancillary Function Driver for WinSock Information Disclosure Vulnerability |
CVE-2026-34348 | Important | Windows Event Logging Service Information Disclosure Vulnerability |
CVE-2026-40378 | Important | Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability |
CVE-2026-42990 | Important | SQL Server ODBC driver Elevation of Privilege Vulnerability |
CVE-2026-44800 | Important | Windows Push Notifications Elevation of Privilege Vulnerability |
CVE-2026-48571 | Important | Windows App Package Installer Elevation of Privilege Vulnerability |
CVE-2026-48572 | Important | Windows App Package Installer Elevation of Privilege Vulnerability |
CVE-2026-49172 | Important | Windows FTP Service Remote Code Execution Vulnerability |
CVE-2026-50471 | Important | Windows NTFS Remote Code Execution Vulnerability |
CVE-2026-50696 | Important | Internet Key Exchange (IKE) Protocol Denial of Service Vulnerability |
CVE-2026-56173 | Important | Windows WebView Elevation of Privilege Vulnerability |
CVE-2026-58601 | Important | Virtual Hard Disk (VHD) Miniport Driver Elevation of Privilege Vulernability |
CVE-2026-58629 | Important | DirectX Graphics Kernel Elevation of Privilege Vulnerability |
CVE-2026-58640 | Important | Windows NTFS Remote Code Execution Vulnerability |
CVE-2026-59116 | Important | Windows Remote Desktop Security Feature Bypass Vulnerability |
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.
- Save your work first.Windows restarts to finish the update, once or twice.
- Open Start → Settings → Windows Update.Select Check for updates. Windows downloads the month’s cumulative update; it includes every earlier fix.
- Restart when it asks.Select Restart now, or schedule it for tonight. Until it restarts, the fixes aren’t in place.
- 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 22631.7517 or later.
Older devices
The same day, Microsoft released KB5101649 (376 security flaws), KB5101650 (373 security flaws) and KB5099539 (309 security flaws) for devices that stay on an older version. Each fixes the same holes where they apply.
Before and after
- After: KB5120240, 11 Aug 2026, 160 security flaws
- Windows updates, every release and the latest version
- Updates, the latest version of everything HARD tracks
References
- ^ Microsoft. “KB5099414”, 14 Jul 2026.