Microsoft · Security update · October 14, 2025

KB5066791: October 2025 cumulative update for Windows 10 21H2

KB5066791, released October 14, 2025, fixes 98 CVEs across 6 products. 3 of them are being exploited (CVE-2025-24990); 3 on CISA KEV. Patch Radar priority: Patch now.

Patch now3 on CISA KEV1 publicly disclosed
CVEs closed
98
2 rated Critical
Exploited
3
CVE-2025-24990
Exploitation more likely
6
Vendor assessment
Highest EPSS
0.0651
93rd percentile

Priority of the 98 CVEs

Patch now 3 Urgent 8 High 57 Routine 30

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-2025-24990 Agere Windows Modem Driver Elevation of Privilege 7.8 0.0651 KEVExploited
Patch now CVE-2025-47827 Windows Secure Boot Security Feature Bypass 4.6 0.0515 KEVExploited
Patch now CVE-2025-59230 Windows Remote Access Connection Manager Elevation of Privilege 7.8 0.0272 KEVExploited
Urgent CVE-2025-55681 Windows DWM Elevation of Privilege 7.0 0.0550 More likely
Urgent CVE-2016-9535 Microsoft Graphics Component Remote Code Execution 4.0 0.0473 Exploitation Unlikely
Urgent CVE-2025-59199 Software Protection Platform (SPP) Elevation of Privilege 7.8 0.0455 More likely
Urgent CVE-2025-55692 Windows Error Reporting Elevation of Privilege 7.8 0.0363 More likely
Urgent CVE-2025-24052 Agere Windows Modem Driver Elevation of Privilege 7.8 0.0254 DisclosedMore likely
Urgent CVE-2025-58722 Windows DWM Elevation of Privilege 7.8 0.0234 More likely
Urgent CVE-2025-49708 Microsoft Graphics Component Elevation of Privilege 9.9 0.0126 Exploitation Less Likely
Urgent CVE-2025-55680 Windows Cloud Files Mini Filter Driver Elevation of Privilege 7.8 0.0044 More likely
High CVE-2025-59295 Internet Explorer Remote Code Execution 8.8 0.0190 Exploitation Less Likely
High CVE-2025-54957 Microsoft Windows Codecs Library Remote Code Execution 7.0 0.0160 Exploitation Less Likely
High CVE-2025-59254 Windows DWM Core Library Elevation of Privilege 7.8 0.0114 Exploitation Unlikely
High CVE-2025-58726 Windows SMB Server Elevation of Privilege 7.5 0.0104 Exploitation Less Likely
High CVE-2025-55326 Connected Devices Platform Service (Cdpsvc) Remote Code Execution 7.5 0.0084 Exploitation Less Likely
High CVE-2025-59200 Data Sharing Service Client Spoofing 7.7 0.0081 Exploitation Less Likely
High CVE-2025-59282 Inbox COM Objects Remote Code Execution 7.0 0.0061 Exploitation Unlikely
High CVE-2025-58718 Remote Desktop Client Remote Code Execution 8.8 0.0060 Exploitation Less Likely
High CVE-2025-59208 Windows MapUrlToZone Information Disclosure 7.1 0.0050 Exploitation Less Likely
High CVE-2025-25004 Microsoft PowerShell Elevation of Privilege 7.3 0.0049 Exploitation Less Likely
High CVE-2025-58732 Inbox COM Objects Remote Code Execution 7.0 0.0047 Exploitation Unlikely
High CVE-2025-58735 Inbox COM Objects Remote Code Execution 7.0 0.0047 Exploitation Unlikely
High CVE-2025-59201 Network Connection Status Indicator (NCSI) Elevation of Privilege 7.8 0.0046 Exploitation Less Likely
High CVE-2025-64679 Windows DWM Core Library Elevation of Privilege 7.8 0.0045 Exploitation Less Likely
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