Windows · Microsoft · released September 8, 2026
Windows security updates, September 2026: every vulnerability, rated
Microsoft published 705 Windows vulnerabilities in September 2026, most of them on Patch Tuesday, September 8, 2026. 71 are rated Critical. 1 was already being exploited, so it goes to the top of the list. 119 more deserve attention this week; 585 can follow the normal monthly rollout. 27 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
- 705
- Patch now
- 1
- This week
- 119
- Normal cycle
- 543
- Low
- 42
Fixed in: September 2026 Windows security update restart requiredMicrosoft release notes
Page 1 of 12 · sorted by risk, then score
Patch now1 on this page
- Patch nowWindowsSeptember 8, 2026
CVE-2026-85880Windows Advanced Local Procedure Call (ALPC)
Elevation of Privilege · Severity Important · CVSS 7.8 · EPSS 0.04
In Windows Advanced Local Procedure Call (ALPC), 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 reports it has been exploited in real attacks. CISA lists it as a Known Exploited Vulnerability, meaning attacks have been seen (added 2026-09-08; federal agencies must fix it by 2026-09-22). EPSS score 0.04, the modelled probability of exploitation activity in the next 30 days. Fixed in the September 2026 Windows security update (KB5122876, KB5122878, KB5122882) for 20 supported Windows versions; a restart is required.
This week59 on this page
- This weekWindowsSeptember 8, 2026
CVE-2026-69525Remote Desktop Services
Remote Code Execution · Severity Important · CVSS 9.8
In Remote Desktop Services, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Important, CVSS 9.8. Microsoft rates it "exploitation more likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69579Windows Message Queuing
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Message Queuing, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69590Windows Routing and Remote Access Service (RRAS)
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Routing and Remote Access Service (RRAS), an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69595Windows Services for NFS ONCRPC XDR Driver
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Services for NFS ONCRPC XDR Driver, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 12 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69730Windows DNS Server
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows DNS Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation more likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69769Windows HTTP Print Provider
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows HTTP Print Provider, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69829Windows Shell
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Shell, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69845Windows DHCP Server
Remote Code Execution · Severity Critical · CVSS 9.8 · EPSS 0.01
In Windows DHCP Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". EPSS score 0.01, the modelled probability of exploitation activity in the next 30 days. Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-70296Windows Imaging Component
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Imaging Component, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72979Windows DHCP Server
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows DHCP Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72982Windows Netlogon
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Netlogon, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72983Internet Connection Sharing (ICS)
Remote Code Execution · Severity Critical · CVSS 9.8
In Internet Connection Sharing (ICS), an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-73010Microsoft Failover Cluster
Remote Code Execution · Severity Critical · CVSS 9.8
In Microsoft Failover Cluster, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 8 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-77493Windows Graphics Component
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Graphics Component, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-78445Windows Services for NFS ONCRPC XDR Driver
Remote Code Execution · Severity Critical · CVSS 9.8
In Windows Services for NFS ONCRPC XDR Driver, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 9.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 12 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69499Windows Imaging Component
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Imaging Component, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69518Windows Remote Desktop
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Remote Desktop, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69601Microsoft Windows Media Foundation
Remote Code Execution · Severity Critical · CVSS 8.8
In Microsoft Windows Media Foundation, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69603Windows Hyper-V
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Hyper-V, an attacker with an ordinary user account could run their own code once they can run code on the PC. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 28 supported Windows versions; a restart is required.
- This weekWindowsSeptember 30, 2026
CVE-2026-69712Windows Key Distribution Center
Remote Code Execution · Severity Critical · CVSS 8.8 · Out of band
In Windows Key Distribution Center, an attacker with an ordinary user account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 12 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69740Windows Hello
Elevation of Privilege · Severity Critical · CVSS 8.8
In Windows Hello, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122880, KB5124008, KB5124012) for 8 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69784Windows Hello
Elevation of Privilege · Severity Critical · CVSS 8.8
In Windows Hello, an attacker with an ordinary user account could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122878, KB5122880, KB5124008) for 14 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69860Windows Imaging Component
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Imaging Component, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-70203Windows Media Player
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Media Player, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-70586Windows Paint
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Paint, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72940Windows Schannel
Remote Code Execution · Severity Important · CVSS 8.8
In Windows Schannel, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Important, CVSS 8.8. Microsoft rates it "exploitation more likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122880, KB5122882) for 12 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72950Windows Routing and Remote Access Service (RRAS)
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Routing and Remote Access Service (RRAS), an attacker with an ordinary user account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72959Windows Routing and Remote Access Service (RRAS)
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Routing and Remote Access Service (RRAS), an attacker with an ordinary user account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72960Windows Media Player
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Media Player, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 26 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72986Graphic Fonts
Remote Code Execution · Severity Critical · CVSS 8.8
In Graphic Fonts, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-73006DirectWrite
Remote Code Execution · Severity Critical · CVSS 8.8
In DirectWrite, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 26 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-73013Windows Imaging Component
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Imaging Component, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-73018Graphic Fonts
Remote Code Execution · Severity Critical · CVSS 8.8
In Graphic Fonts, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-73023Windows Imaging Component
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Imaging Component, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-77495Windows Imaging Component
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Imaging Component, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-77504Microsoft Office Word
Remote Code Execution · Severity Critical · CVSS 8.8
In Microsoft Office Word, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-80083Windows Hyper-V
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Hyper-V, an attacker with an ordinary user account could run their own code once they can run code on the PC. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122880, KB5122882) for 12 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-81955Windows Graphics Component
Remote Code Execution · Severity Critical · CVSS 8.8
In Windows Graphics Component, an attacker with no account could run their own code over the network, but only if someone opens a file, link or message. Microsoft severity Critical, CVSS 8.8. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5002916, KB5122871, KB5122874) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69820Windows Hello
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Hello, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122878, KB5122880, KB5124008) for 14 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69846Windows Secure Kernel Mode
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Secure Kernel Mode, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 26 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69874Windows ALPC
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows ALPC, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 22 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69906Windows Secure Kernel Mode
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Secure Kernel Mode, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 26 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72958Windows Credential Guard
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Credential Guard, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5124008, KB5124012) for 8 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72961Windows Hyper-V
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Hyper-V, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 26 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72962Windows USB Video Driver
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows USB Video Driver, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 22 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-81354Windows Hello
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Hello, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122876, KB5122878, KB5122880) for 18 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-83939Windows Secure Kernel Mode
Elevation of Privilege · Severity Critical · CVSS 8.2
In Windows Secure Kernel Mode, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5124012) for 2 supported Windows versions; a restart is required.
- This weekWindowsSeptember 27, 2026
CVE-2026-85921Windows Secure Kernel Mode
Elevation of Privilege · Severity Critical · CVSS 8.2 · Out of band
In Windows Secure Kernel Mode, an attacker who already has admin rights could take higher privileges once they can run code on the PC. Microsoft severity Critical, CVSS 8.2. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5129194) for 2 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69530Windows Reliable Multicast Transport Driver (RMCAST)
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows Reliable Multicast Transport Driver (RMCAST), an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 8 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69813Windows DNS Server
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows DNS Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69827Windows DNS Server
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows DNS Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-69858Windows DNS Server
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows DNS Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122882) for 4 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-70342Windows Ancillary Function Driver for WinSock
Elevation of Privilege · Severity Important · CVSS 8.1
In Windows Ancillary Function Driver for WinSock, an attacker with no account could take higher privileges over the network without anyone clicking anything. Microsoft severity Important, CVSS 8.1. Microsoft rates it "exploitation more likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72981IP Helper
Remote Code Execution · Severity Critical · CVSS 8.1
In IP Helper, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-72987Windows DNS
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows DNS, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation unlikely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-77505Windows DNS Server
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows DNS Server, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 16 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-78444Microsoft Failover Cluster
Remote Code Execution · Severity Critical · CVSS 8.1
In Microsoft Failover Cluster, an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 8 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-78449Windows Reliable Multicast Transport Driver (RMCAST)
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows Reliable Multicast Transport Driver (RMCAST), an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122878) for 30 supported Windows versions; a restart is required.
- This weekWindowsSeptember 8, 2026
CVE-2026-78450Windows Reliable Multicast Transport Driver (RMCAST)
Remote Code Execution · Severity Critical · CVSS 8.1
In Windows Reliable Multicast Transport Driver (RMCAST), an attacker with no account could run their own code over the network without anyone clicking anything. Microsoft severity Critical, CVSS 8.1. Microsoft rates it "exploitation less likely". Fixed in the September 2026 Windows security update (KB5122871, KB5122876, KB5122882) for 8 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.