Microsoft · Security update · September 8, 2026

KB5122878: September 2026 cumulative update for Windows 10 21H2

KB5122878, released September 8, 2026, fixes 575 CVEs across 6 products. One of them is being exploited (CVE-2026-85880); 1 on CISA KEV. Patch Radar priority: Patch now.

Patch now1 on CISA KEV
CVEs closed
575
49 rated Critical
Exploited
1
CVE-2026-85880
Exploitation more likely
49
Vendor assessment
Highest EPSS
0.0280
86th percentile

Priority of the 575 CVEs

Patch now 1 Urgent 96 High 369 Routine 109

Applies to

Product
Windows 10 Version 21H2 for 32-bit Systems
Windows 10 Version 21H2 for ARM64-based Systems
Windows 10 Version 21H2 for x64-based Systems
Windows 10 Version 22H2 for 32-bit Systems
Windows 10 Version 22H2 for ARM64-based Systems
Windows 10 Version 22H2 for x64-based Systems

CVEs this fix closes

PriorityCVEComponentImpactCVSSEPSSExploitation
Patch now CVE-2026-85880 Windows ALPC Elevation of Privilege 7.8 0.0039 KEVExploited
Urgent CVE-2026-69525 Windows Remote Desktop Services Remote Code Execution 9.8 0.0097 More likely
Urgent CVE-2026-69579 Windows Message Queuing Remote Code Execution 9.8 0.0097 Exploitation Unlikely
Urgent CVE-2026-69590 Windows Routing and Remote Access Service (RRAS) Remote Code Execution 9.8 0.0097 Exploitation Less Likely
Urgent CVE-2026-69769 Windows HTTP Print Provider Remote Code Execution 9.8 0.0097 Exploitation Unlikely
Urgent CVE-2026-69829 Windows Shell Remote Code Execution 9.8 0.0097 Exploitation Unlikely
Urgent CVE-2026-70296 Windows Imaging Component Remote Code Execution 9.8 0.0097 Exploitation Less Likely
Urgent CVE-2026-72982 Windows Netlogon Remote Code Execution 9.8 0.0097 Exploitation Unlikely
Urgent CVE-2026-72983 Windows Internet Connection Sharing (ICS) Remote Code Execution 9.8 0.0097 Exploitation Less Likely
Urgent CVE-2026-73009 Windows Secure Socket Tunneling Protocol (SSTP) Remote Code Execution 9.8 0.0097 Exploitation Less Likely
Urgent CVE-2026-77493 Microsoft Graphics Component Remote Code Execution 9.8 0.0097 Exploitation Less Likely
Urgent CVE-2026-72950 Windows Routing and Remote Access Service (RRAS) Remote Code Execution 8.8 0.0092 Exploitation Unlikely
Urgent CVE-2026-72959 Windows Routing and Remote Access Service (RRAS) Remote Code Execution 8.8 0.0091 Exploitation Less Likely
Urgent CVE-2026-69723 Windows Kernel Information Disclosure 5.7 0.0089 More likely
Urgent CVE-2026-81955 Microsoft Graphics Component Remote Code Execution 8.8 0.0084 Exploitation Unlikely
Urgent CVE-2026-69499 Windows Imaging Component Remote Code Execution 8.8 0.0082 Exploitation Less Likely
Urgent CVE-2026-69518 Windows Remote Desktop Remote Code Execution 8.8 0.0082 Exploitation Less Likely
Urgent CVE-2026-69601 Microsoft Windows Media Foundation Remote Code Execution 8.8 0.0082 Exploitation Less Likely
Urgent CVE-2026-69860 Windows Imaging Component Remote Code Execution 8.8 0.0082 Exploitation Unlikely
Urgent CVE-2026-70203 Windows Media Player Remote Code Execution 8.8 0.0082 Exploitation Less Likely
Urgent CVE-2026-70586 Windows Paint Remote Code Execution 8.8 0.0082 Exploitation Unlikely
Urgent CVE-2026-72960 Windows Media Player Remote Code Execution 8.8 0.0082 Exploitation Unlikely
Urgent CVE-2026-72986 Graphic Fonts Remote Code Execution 8.8 0.0082 Exploitation Less Likely
Urgent CVE-2026-73006 Microsoft Graphics Component Remote Code Execution 8.8 0.0082 Exploitation Less Likely
Urgent CVE-2026-73013 Windows Imaging Component Remote Code Execution 8.8 0.0082 Exploitation Less Likely
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