# KB5073724: January 2026 cumulative update for Windows 10 21H2 KB5073724, released January 13, 2026, fixes 72 CVEs across 6 products. One of them is being exploited (CVE-2026-20805); 1 on CISA KEV. Patch Radar priority: Patch now. - Web page: https://patchblox.com/security/fix/microsoft/kb5073724 - Platform: Microsoft - Released: Jan 13, 2026 - Priority: Patch now (Closes CVE-2026-20805, exploited (CISA KEV)) - CVEs: 72, exploited: 1, on CISA KEV: 1 - Vendor advisory: https://support.microsoft.com/help/5073724 ## Applies to | Product | Release | Fixed in | |---|---|---| | [Windows 10 Version 21H2 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-21h2-for-32-bit-systems.md) | | | | [Windows 10 Version 21H2 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-21h2-for-arm64-based-systems.md) | | | | [Windows 10 Version 21H2 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-21h2-for-x64-based-systems.md) | | | | [Windows 10 Version 22H2 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-22h2-for-32-bit-systems.md) | | | | [Windows 10 Version 22H2 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-22h2-for-arm64-based-systems.md) | | | | [Windows 10 Version 22H2 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-22h2-for-x64-based-systems.md) | | | ## CVEs this fix closes | CVE | Priority | Component | CVSS | EPSS | Exploitation | |---|---|---|---:|---:|---| | [CVE-2026-20805](https://patchblox.com/security/data/cve/CVE-2026-20805.md) | Patch now | Desktop Window Manager | 5.5 | 0.0746 | CISA KEV | | [CVE-2026-20860](https://patchblox.com/security/data/cve/CVE-2026-20860.md) | Urgent | Windows Ancillary Function Driver for WinSock | 7.8 | 0.0828 | More likely | | [CVE-2026-20817](https://patchblox.com/security/data/cve/CVE-2026-20817.md) | Urgent | Windows Error Reporting | 7.8 | 0.0542 | More likely | | [CVE-2026-20840](https://patchblox.com/security/data/cve/CVE-2026-20840.md) | Urgent | Windows NTFS | 7.8 | 0.0459 | More likely | | [CVE-2026-20871](https://patchblox.com/security/data/cve/CVE-2026-20871.md) | Urgent | Desktop Window Manager | 7.8 | 0.0414 | More likely | | [CVE-2026-20843](https://patchblox.com/security/data/cve/CVE-2026-20843.md) | Urgent | Windows Routing and Remote Access Service (RRAS) | 7.8 | 0.0342 | More likely | | [CVE-2026-20820](https://patchblox.com/security/data/cve/CVE-2026-20820.md) | Urgent | Windows Common Log File System Driver | 7.8 | 0.0256 | More likely | | [CVE-2026-20816](https://patchblox.com/security/data/cve/CVE-2026-20816.md) | Urgent | Windows Installer | 7.8 | 0.0244 | More likely | | [CVE-2026-20922](https://patchblox.com/security/data/cve/CVE-2026-20922.md) | Urgent | Windows NTFS | 7.8 | 0.0108 | More likely | | [CVE-2023-31096](https://patchblox.com/security/data/cve/CVE-2023-31096.md) | Urgent | Agere Windows Modem Driver | 7.8 | 0.0048 | Disclosed | | [CVE-2026-20822](https://patchblox.com/security/data/cve/CVE-2026-20822.md) | Urgent | Microsoft Graphics Component | 7.8 | 0.0039 | | | [CVE-2026-20929](https://patchblox.com/security/data/cve/CVE-2026-20929.md) | High | Windows HTTP.sys | 7.5 | 0.0287 | | | [CVE-2026-20875](https://patchblox.com/security/data/cve/CVE-2026-20875.md) | High | Windows Local Security Authority Subsystem Service (LSASS) | 7.5 | 0.0154 | | | [CVE-2026-20868](https://patchblox.com/security/data/cve/CVE-2026-20868.md) | High | Windows Routing and Remote Access Service (RRAS) | 8.8 | 0.0139 | | | [CVE-2026-20921](https://patchblox.com/security/data/cve/CVE-2026-20921.md) | High | Windows SMB Server | 7.5 | 0.0118 | | | [CVE-2024-55414](https://patchblox.com/security/data/cve/CVE-2024-55414.md) | High | Windows Motorola Soft Modem Driver | 7.8 | 0.0114 | | | [CVE-2026-20856](https://patchblox.com/security/data/cve/CVE-2026-20856.md) | High | Windows Server Update Service | 8.1 | 0.0112 | | | [CVE-2026-20849](https://patchblox.com/security/data/cve/CVE-2026-20849.md) | High | Windows Kerberos | 7.5 | 0.0101 | | | [CVE-2026-20931](https://patchblox.com/security/data/cve/CVE-2026-20931.md) | High | Windows Telephony Service | 8.0 | 0.0085 | | | [CVE-2026-20919](https://patchblox.com/security/data/cve/CVE-2026-20919.md) | High | Windows SMB Server | 7.5 | 0.0080 | | | [CVE-2026-20926](https://patchblox.com/security/data/cve/CVE-2026-20926.md) | High | Windows SMB Server | 7.5 | 0.0080 | | | [CVE-2026-20848](https://patchblox.com/security/data/cve/CVE-2026-20848.md) | High | Windows SMB Server | 7.5 | 0.0075 | | | [CVE-2026-20934](https://patchblox.com/security/data/cve/CVE-2026-20934.md) | High | Windows SMB Server | 7.5 | 0.0075 | | | [CVE-2026-20837](https://patchblox.com/security/data/cve/CVE-2026-20837.md) | High | Windows Media | 7.8 | 0.0068 | | | [CVE-2026-20864](https://patchblox.com/security/data/cve/CVE-2026-20864.md) | High | Connected Devices Platform Service (Cdpsvc) | 7.8 | 0.0055 | | | [CVE-2026-20804](https://patchblox.com/security/data/cve/CVE-2026-20804.md) | High | Windows Hello | 7.7 | 0.0050 | | | [CVE-2026-20852](https://patchblox.com/security/data/cve/CVE-2026-20852.md) | High | Windows Hello | 7.7 | 0.0050 | | | [CVE-2026-20810](https://patchblox.com/security/data/cve/CVE-2026-20810.md) | High | Windows Ancillary Function Driver for WinSock | 7.8 | 0.0049 | | | [CVE-2026-20832](https://patchblox.com/security/data/cve/CVE-2026-20832.md) | High | Windows Remote Procedure Call Interface Definition Language (IDL) | 7.8 | 0.0048 | | | [CVE-2026-20857](https://patchblox.com/security/data/cve/CVE-2026-20857.md) | High | Windows Cloud Files Mini Filter Driver | 7.8 | 0.0048 | | | [CVE-2026-20940](https://patchblox.com/security/data/cve/CVE-2026-20940.md) | High | Windows Cloud Files Mini Filter Driver | 7.8 | 0.0046 | | | [CVE-2026-20923](https://patchblox.com/security/data/cve/CVE-2026-20923.md) | High | Windows Management Services | 7.8 | 0.0040 | | | [CVE-2026-20865](https://patchblox.com/security/data/cve/CVE-2026-20865.md) | High | Windows Management Services | 7.8 | 0.0039 | | | [CVE-2026-20842](https://patchblox.com/security/data/cve/CVE-2026-20842.md) | High | Windows DWM | 7.0 | 0.0039 | | | [CVE-2026-20809](https://patchblox.com/security/data/cve/CVE-2026-20809.md) | High | Windows Kernel Memory | 7.8 | 0.0036 | | | [CVE-2026-20844](https://patchblox.com/security/data/cve/CVE-2026-20844.md) | High | Windows Clipboard Server | 7.4 | 0.0032 | | | [CVE-2026-20853](https://patchblox.com/security/data/cve/CVE-2026-20853.md) | High | Windows WalletService | 7.4 | 0.0031 | | | [CVE-2026-20877](https://patchblox.com/security/data/cve/CVE-2026-20877.md) | High | Windows Management Services | 7.8 | 0.0030 | | | [CVE-2026-20918](https://patchblox.com/security/data/cve/CVE-2026-20918.md) | High | Windows Management Services | 7.8 | 0.0030 | | | [CVE-2026-20924](https://patchblox.com/security/data/cve/CVE-2026-20924.md) | High | Windows Management Services | 7.8 | 0.0030 | | | [CVE-2026-20826](https://patchblox.com/security/data/cve/CVE-2026-20826.md) | High | Tablet Windows User Interface (TWINUI) Subsystem | 7.8 | 0.0030 | | | [CVE-2026-20831](https://patchblox.com/security/data/cve/CVE-2026-20831.md) | High | Windows Ancillary Function Driver for WinSock | 7.8 | 0.0030 | | | [CVE-2026-20858](https://patchblox.com/security/data/cve/CVE-2026-20858.md) | High | Windows Management Services | 7.8 | 0.0029 | | | [CVE-2026-20861](https://patchblox.com/security/data/cve/CVE-2026-20861.md) | High | Windows Management Services | 7.8 | 0.0029 | | | [CVE-2026-20866](https://patchblox.com/security/data/cve/CVE-2026-20866.md) | High | Windows Management Services | 7.8 | 0.0029 | | | [CVE-2026-20867](https://patchblox.com/security/data/cve/CVE-2026-20867.md) | High | Windows Management Services | 7.8 | 0.0029 | | | [CVE-2026-20873](https://patchblox.com/security/data/cve/CVE-2026-20873.md) | High | Windows Management Services | 7.8 | 0.0029 | | | [CVE-2026-20874](https://patchblox.com/security/data/cve/CVE-2026-20874.md) | High | Windows Management Services | 7.8 | 0.0029 | | | [CVE-2026-20814](https://patchblox.com/security/data/cve/CVE-2026-20814.md) | High | Graphics Kernel | 7.0 | 0.0029 | | | [CVE-2026-20869](https://patchblox.com/security/data/cve/CVE-2026-20869.md) | High | Windows Local Session Manager (LSM) | 7.0 | 0.0029 | | | [CVE-2026-20836](https://patchblox.com/security/data/cve/CVE-2026-20836.md) | High | Graphics Kernel | 7.0 | 0.0029 | | | [CVE-2026-20872](https://patchblox.com/security/data/cve/CVE-2026-20872.md) | Routine | Windows NTLM | 6.5 | 0.1979 | | | [CVE-2026-20925](https://patchblox.com/security/data/cve/CVE-2026-20925.md) | Routine | Windows NTLM | 6.5 | 0.1793 | | | [CVE-2026-20847](https://patchblox.com/security/data/cve/CVE-2026-20847.md) | Routine | Windows Shell | 6.5 | 0.0134 | | | [CVE-2026-20812](https://patchblox.com/security/data/cve/CVE-2026-20812.md) | Routine | Windows LDAP - Lightweight Directory Access Protocol | 6.5 | 0.0112 | | | [CVE-2026-21265](https://patchblox.com/security/data/cve/CVE-2026-21265.md) | Routine | Windows Secure Boot | 6.4 | 0.0110 | Disclosed | | [CVE-2026-20927](https://patchblox.com/security/data/cve/CVE-2026-20927.md) | Routine | Windows SMB Server | 5.3 | 0.0091 | | | [CVE-2026-20824](https://patchblox.com/security/data/cve/CVE-2026-20824.md) | Routine | Windows Remote Assistance | 5.5 | 0.0086 | | | [CVE-2026-20834](https://patchblox.com/security/data/cve/CVE-2026-20834.md) | Routine | Windows Shell | 4.6 | 0.0074 | | | [CVE-2026-20821](https://patchblox.com/security/data/cve/CVE-2026-20821.md) | Routine | Windows Remote Procedure Call | 6.2 | 0.0070 | | | [CVE-2026-20932](https://patchblox.com/security/data/cve/CVE-2026-20932.md) | Routine | Windows File Explorer | 5.5 | 0.0068 | | | [CVE-2026-20823](https://patchblox.com/security/data/cve/CVE-2026-20823.md) | Routine | Windows File Explorer | 5.5 | 0.0066 | | | [CVE-2026-20827](https://patchblox.com/security/data/cve/CVE-2026-20827.md) | Routine | Tablet Windows User Interface (TWINUI) Subsystem | 5.5 | 0.0066 | | | [CVE-2026-20828](https://patchblox.com/security/data/cve/CVE-2026-20828.md) | Routine | Windows Internet Connection Sharing (ICS) | 4.6 | 0.0064 | | | [CVE-2026-20862](https://patchblox.com/security/data/cve/CVE-2026-20862.md) | Routine | Windows Management Services | 5.5 | 0.0064 | | | [CVE-2026-20829](https://patchblox.com/security/data/cve/CVE-2026-20829.md) | Routine | Windows TPM | 5.5 | 0.0056 | | | [CVE-2026-20825](https://patchblox.com/security/data/cve/CVE-2026-20825.md) | Routine | Windows Hyper-V | 4.4 | 0.0053 | | | [CVE-2026-20939](https://patchblox.com/security/data/cve/CVE-2026-20939.md) | Routine | Windows File Explorer | 5.5 | 0.0051 | | | [CVE-2026-20937](https://patchblox.com/security/data/cve/CVE-2026-20937.md) | Routine | Windows File Explorer | 5.5 | 0.0051 | | | [CVE-2026-20936](https://patchblox.com/security/data/cve/CVE-2026-20936.md) | Routine | Windows NDIS | 4.3 | 0.0048 | | | [CVE-2026-20839](https://patchblox.com/security/data/cve/CVE-2026-20839.md) | Routine | Windows Client-Side Caching (CSC) Service | 5.5 | 0.0048 | | | [CVE-2026-20962](https://patchblox.com/security/data/cve/CVE-2026-20962.md) | Routine | Dynamic Root of Trust for Measurement (DRTM) | 4.4 | 0.0044 | | --- Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.