Windows · Microsoft · released October 13, 2026
Windows security updates, October 2026: every vulnerability, rated
Microsoft published 1,165 Windows vulnerabilities in October 2026, most of them on Patch Tuesday, October 13, 2026. 42 are rated Critical. 2 were already being exploited, so they go to the top of the list. 158 more deserve attention this week; 1,005 can follow the normal monthly rollout. 51 were fixed by an earlier update and only disclosed this month, so a PC that is already current is covered. The updates that carry these fixes need a restart.
- CVEs
- 1,165
- Patch now
- 2
- This week
- 158
- Normal cycle
- 972
- Low
- 33
Fixed in: October 2026 Windows security update restart requiredMicrosoft release notes
Page 7 of 20 · sorted by risk, then score
Normal cycle60 on this page · tap one for its risk review
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70123Microsoft Graphics Component
Elevation of Privilege · Severity Important · CVSS 7.8
In Microsoft Graphics Component, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70131Microsoft Windows Media Foundation
Elevation of Privilege · Severity Important · CVSS 7.8
In Microsoft Windows Media Foundation, an attacker with no account could take higher privileges once they can run code on the PC, but only if someone opens a file, link or message. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70138Windows OLE
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows OLE, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70139Windows Update Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Update Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70142Windows Update Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Update Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5127646) for 12 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70143Windows Network File System
Remote Code Execution · Severity Important · CVSS 7.8
In Windows Network File System, an attacker with an ordinary user account could run their own code once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70172Windows NTFS
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70177Microsoft Windows Search Component
Elevation of Privilege · Severity Important · CVSS 7.8
In Microsoft Windows Search Component, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70184Windows Backup Engine
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Backup Engine, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126653, KB5126657, KB5127646) for 16 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70222Windows Shell
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Shell, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70225Windows Ancillary Function Driver for WinSock
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Ancillary Function Driver for WinSock, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70228Desktop Window Manager
Elevation of Privilege · Severity Important · CVSS 7.8
In Desktop Window Manager, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 24 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70238Windows Storage Spaces Controller
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Storage Spaces Controller, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70247HTTP.sys
Remote Code Execution · Severity Important · CVSS 7.8
In HTTP.sys, an attacker with an ordinary user account could run their own code once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70274Windows Bind Filter Driver
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Bind Filter Driver, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5127646) for 12 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70278Microsoft Windows Media Foundation
Elevation of Privilege · Severity Important · CVSS 7.8
In Microsoft Windows Media Foundation, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70285Windows Win32k
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Win32k, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 28 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-70566Windows Schannel
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Schannel, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 14, 2026
CVE-2026-70584Windows Core Messaging
Elevation of Privilege · Severity Important · CVSS 7.8 · Fixed earlier (September 2026)
In Windows Core Messaging, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Microsoft disclosed it on October 14, 2026, but the fix had already shipped in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 26 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-73027Windows Setup Files Cleanup
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Setup Files Cleanup, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-78459Microsoft Internet Information Services
Elevation of Privilege · Severity Important · CVSS 7.8
In Microsoft Internet Information Services, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-81969Windows Server Update Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Server Update Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126655) for 16 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83499Windows Server Update Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Server Update Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126655) for 16 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83506Servicing Stack Updates
Elevation of Privilege · Severity Important · CVSS 7.8
In Servicing Stack Updates, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83508Windows NTFS
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83513Windows Universal Disk Format File System Driver (UDFS)
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Universal Disk Format File System Driver (UDFS), an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83514Windows Partition Management Driver
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Partition Management Driver, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83518RPC Runtime
Elevation of Privilege · Severity Important · CVSS 7.8
In RPC Runtime, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5122880, KB5124008, KB5124012) for 8 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83567Windows NTFS
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83568Windows Kernel-Mode Drivers
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Kernel-Mode Drivers, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5127646, KB5127648) for 10 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83569HID Parser Library
Elevation of Privilege · Severity Important · CVSS 7.8
In HID Parser Library, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 24 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83570Windows Search Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Search Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 30 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83579Windows Smart Card
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Smart Card, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83583Windows Geotag Broker
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Geotag Broker, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 28 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83585Windows NTFS
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83586Windows Resilient File System (ReFS) Deduplication Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Resilient File System (ReFS) Deduplication Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5127646) for 12 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83587Windows Core Messaging
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Core Messaging, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 28 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83588Windows USB Driver
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows USB Driver, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83634Windows BitLocker
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows BitLocker, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5126655) for 14 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83637Windows Kernel-Mode Drivers
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Kernel-Mode Drivers, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 24 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83638Windows USB Driver
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows USB Driver, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83639Windows Sensor Data Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Sensor Data Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 28 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83640Windows NTFS
Remote Code Execution · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could run their own code once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83641Windows Media
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Media, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83650Windows Media
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Media, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83652Windows NTFS
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83654Windows Modern Device Management (MDM)
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Modern Device Management (MDM), an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5126655) for 20 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83659Windows User Profile Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows User Profile Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83678Windows TCP/IP
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows TCP/IP, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83679Windows Defender Firewall Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Defender Firewall Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5127646) for 12 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83690Windows Kernel
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Kernel, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 24 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83691Windows DHCP Server
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows DHCP Server, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83692Windows Bind Filter Driver
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Bind Filter Driver, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126653, KB5126655) for 20 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83698Windows Client-Side Caching (CSC) Service
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Client-Side Caching (CSC) Service, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83700Windows Now Playing Session Manager
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Now Playing Session Manager, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 24 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83709Windows NTLM
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows NTLM, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 28 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83712Windows NTFS
Remote Code Execution · Severity Important · CVSS 7.8
In Windows NTFS, an attacker with an ordinary user account could run their own code once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 24 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83721Win32k
Elevation of Privilege · Severity Important · CVSS 7.8
In Win32k, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5127646, KB5127648) for 10 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83726Windows DWM Core Library
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows DWM Core Library, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation less likely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 28 supported Windows versions; a restart is required.
- Normal cycleWindowsOctober 13, 2026
CVE-2026-83727Windows Overlay Filter
Elevation of Privilege · Severity Important · CVSS 7.8
In Windows Overlay Filter, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Important, CVSS 7.8. Microsoft rates it "exploitation unlikely". Fixed in the October 2026 Windows security update (KB5126646, KB5126651, KB5126653) for 32 supported Windows versions; a restart is required.
Why an MSP manages this
Reading the list is the easy part
Nobody running a business reads all of them, and nobody should have to. The work is deciding which ones matter today, testing the fixes, getting them onto every PC and Mac without breaking the workday, and proving it was done.
- 01
Triage that starts with the exploited ones
Most of these fixes can ride the normal monthly rollout. A handful need action the same day. Telling them apart, every month, on every machine, is the core of the work, and it is the part an office manager rarely has time for.
- 02
Testing before everyone gets it
Updates go to a test ring and a pilot group first, so a broken accounting package or design tool shows up on two machines instead of forty, and the rollout pauses until it is sorted.
- 03
Restarts that don't wreck the workday
Windows updates usually need a restart and macOS updates often do. Deadlines, maintenance windows and grace periods get the fix installed without forcing a reboot in the middle of a client call.
- 04
Macs managed as seriously as PCs
Windows patching tools don't patch Macs. macOS updates need their own install-by deadlines through device management, and major upgrades need the same compatibility testing a Windows feature update gets.
- 05
A plan for machines that can't update
Hardware that ages out and versions past end of support stop getting every fix. They need a decision, isolate, upgrade or replace, before they become the easiest way in.
- 06
Proof when someone asks
Cyber insurance applications, customer security questionnaires and frameworks such as the FTC Safeguards Rule all ask how you keep systems patched. A managed service keeps the inventory and the reports that answer them.
The ins and outs
What keeping Windows and Mac patched actually involves
Windows
Patch Tuesday, and the exceptions
Microsoft ships security updates on the second Tuesday of each month, and out of band when something can't wait. This log marks the out-of-band ones.
Cumulative updates
Each month's Windows update carries the earlier months' fixes, so a PC that missed one catches up with the next, as long as it actually installs.
Fixed first, announced later
Some fixes ship before the vulnerability is disclosed. This log flags them, because a PC that is already current is already covered.
Rings, deferrals and deadlines
Windows Update for Business and Intune let you delay updates for a test group, set an install-by deadline and give a grace period before a forced restart.
Known Issue Rollback and safeguard holds
Microsoft can quietly roll back a change that breaks something, and holds back feature updates from PCs it knows will have trouble. Both explain why two PCs on the same network can be on different builds.
Feature updates and end of support
Each Windows version is serviced for a fixed period. Windows 10 PCs past end of support only get security fixes through the paid Extended Security Updates program.
Mac
No fixed release day
Apple publishes security updates when they are ready, often several times a month around a major release, so Mac patching runs on alerts, not a calendar.
Updates versus upgrades
A point update (26.7 to 26.7.1) fixes problems. A major upgrade (Tahoe to Golden Gate) changes the system and needs the same app testing as a Windows feature update.
Older versions get some fixes, not all
Apple's deployment guide says not every security issue is fixed in previous major versions. Staying a version behind is a choice with a cost, not a safe default.
Install-by deadlines through device management
Without enforcement, a macOS update prompt can be put off again and again. Device management can set a deadline so the update installs on schedule.
Macs that age out
When a Mac can no longer run a current macOS version, it stops getting the full set of fixes. Inventory by model and macOS version shows which ones are next.
Apple Business for zero-touch setup
New Macs enrolled through Apple Business arrive already managed, so update policy applies from the first login instead of after someone remembers to enroll them.
Both platforms
Third-party apps aren't on these lists
Browsers, PDF readers, accounting software, VPN clients and plug-ins patch on their own schedules. A machine can be current on Windows or macOS and still exposed through an app.
Firmware and drivers
BIOS and UEFI firmware, docks and network gear get security fixes too, and they rarely update themselves.
Recovery keys before big changes
Before a feature update or a major macOS upgrade, confirm BitLocker and FileVault recovery keys are escrowed somewhere you can reach.
Laptops that are rarely in the office
Remote and travelling staff need updates delivered over the internet with the same deadlines as office machines, or they drift months behind.
You can't patch what you can't see
An up-to-date inventory of every PC and Mac, with its version and last update, is what turns a list like this one into a finished job.