Patch Tuesday October 2026: what's exploited and what to install first
Microsoft released fixes for 1408 vulnerabilities on Oct 13, 2026. 1 is already being exploited by attackers, so install that fix first. 1 was publicly disclosed before the fix came out. 77 are rated Critical.
Install these first: already exploited
- Windows ShellExploitedImportantCVSS 8.8A Windows flaw lets booby-trapped files skip the “Are you sure?” warning
What to do: Open Settings, go to Windows Update, select Check for updates, then install and restart. October was also the last update for Windows 11 24H2 Home and Pro, so upgrade if you're on that version.
Publicly disclosed before the fix
Details were public before Microsoft's update, so attacks often follow quickly.
Critical fixes
- CVSS 9.8 Windows Message Queuing Queue Manager Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft QUIC Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft QUIC Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft PostScript Printer Driver Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft PostScript Printer Driver Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft Office Outlook Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft Office Outlook Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft Office Word Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft Office Outlook Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft Office PowerPoint Remote Code Execution Vulnerability
- CVSS 9.8 Windows DHCP Server Remote Code Execution Vulnerability
- CVSS 9.8 Microsoft Office Outlook Remote Code Execution Vulnerability
How to install this month's updates
- Windows PCs: Settings → Windows Update → Check for updates, install, and restart. Restarting is what actually applies the fix.
- Managed fleets: approve this month's updates in Intune, Windows Update for Business or WSUS, and push the exploited fixes first instead of waiting for your normal ring schedule.
- Microsoft 365 Apps / Office: usually updates itself; in any Office app, File → Account → Update Options → Update Now to make sure.
- Servers: Exchange, SharePoint and SQL Server need their own update packages; they don't come through Windows Update alone.
- Check it worked: confirm the build number afterwards (run
winver) or check with our version checker.
By type
| Type | Fixes |
|---|---|
| Elevation of Privilege | 674 |
| Remote Code Execution | 314 |
| Information Disclosure | 252 |
| Denial of Service | 71 |
| Security Feature Bypass | 40 |
| Tampering | 29 |
| Spoofing | 27 |
| Not a Vulnerability | 1 |
Most-patched products
| Product | Fixes |
|---|---|
| Microsoft Office Excel | 69 |
| Role: DNS Server | 52 |
| Windows Kernel | 46 |
| Windows Installer | 38 |
| Windows Win32 Kernel Subsystem | 36 |
| Microsoft Office SharePoint | 36 |
| Microsoft Windows Search Component | 29 |
| Windows NTFS | 26 |
The next Patch Tuesday is Nov 10, 2026 (in 5 days). Microsoft usually publishes around 10 a.m. Pacific; this page updates within the hour.
Questions
What should I patch first from Patch Tuesday October 2026?
The 1 exploited flaw: Windows Shell Security Feature Bypass Vulnerability. Attackers are already using it.
When is the next Patch Tuesday?
Nov 10, 2026. Microsoft releases security updates on the second Tuesday of every month.
Source: Microsoft's October 2026 release notes and CISA's exploited-vulnerability catalog. Counts exclude Chromium fixes shipped in Microsoft Edge. Microsoft last revised this release on Nov 5, 2026. General information only; confirm details with Microsoft.