Patch Gap

Windows · updated Oct 27, 2026

Windows: bugs fixed in the February 2026 update were used in real attacks

Patched: update nowBeing attacked nowHigh

Last checked · Check before installing; only use the official link.

Five Windows bugs were being used by attackers at once. Two let a bad link or file skip the warning Windows normally shows. The others let a program that is already on your PC take more control or crash parts of Windows. Microsoft fixed it in the February 2026 Windows update. Any newer monthly update also includes the fix.

Status
Patched: update now
Being attacked?
Yes[6]
Severity
High
Updated

CISA lists these as used in real attacks (added 2026-02-10). Microsoft's Security Update Guide marks them as exploited. Severity: Patch Gap rating: high, because CISA lists it as used in real attacks (we do not copy a score we have not checked). First reported .

Am I affected?

You are at risk only if your Windows PC has not installed any monthly update since February 2026. Open Settings > Windows Update. If it says 'You're up to date', you are covered.

AppDeviceAffectedFixed in
Windows 10 and 11WindowsWindows 10 and 11 PCs without the February 2026 security update or a newer oneFixed by the February 2026 Windows security update (2026-02-10) or any newer monthly update. Microsoft's page lists the exact update for each Windows version.[1][2][3][4][5]

How to check your version

These checks only look. They do not change anything on your computer.

Windows 10 and 11 on Windows

Easy way: Start > Settings > Windows Update. Then click Update history to see recent updates.

Or type this in PowerShellRead-only. It only reads the version and changes nothing.

Get-CimInstance Win32_OperatingSystem | Select-Object Caption,Version,BuildNumber; Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5 HotFixID,InstalledOn

How to fix it

  1. Open Start > Settings > Windows Update.
  2. Click Check for updates.
  3. Let the updates download and install.
  4. Restart your computer when it asks.

More on each app: Is my Windows up to date?

Official links

Check before installing, and only use these official links or the app's own update button.

For AI agents

This page as data: /incidents/windows-attacked-bugs-feb-2026.json. All problems: /feed.json. Use read-only checks only, and ask before installing anything.

Tracking numbers (CVE): CVE-2026-21510, CVE-2026-21513, CVE-2026-21519, CVE-2026-21525, CVE-2026-21533

Sources

  1. MakerMicrosoft Security Update Guide: CVE-2026-21510 (February 2026 update) (Feb 10, 2026)
  2. MakerMicrosoft Security Update Guide: CVE-2026-21513 (February 2026 update) (Feb 10, 2026)
  3. MakerMicrosoft Security Update Guide: CVE-2026-21519 (February 2026 update) (Feb 10, 2026)
  4. MakerMicrosoft Security Update Guide: CVE-2026-21525 (February 2026 update) (Feb 10, 2026)
  5. MakerMicrosoft Security Update Guide: CVE-2026-21533 (February 2026 update) (Feb 10, 2026)
  6. CISACISA: Known Exploited Vulnerabilities catalog entry for CVE-2026-21510, CVE-2026-21513, CVE-2026-21519, CVE-2026-21525, CVE-2026-21533 (added 2026-02-10) (Feb 10, 2026)
  7. NVDNVD: CVE-2026-21510 (Feb 10, 2026)

"Maker", "CISA", "NVD", "GitHub advisory" and "Official notice" are official sources. "Researcher" and "News" are extra context.