# KB5008218: December 2021 cumulative update for Windows 10 1809 KB5008218, released December 14, 2021, fixes 28 CVEs across 5 products. One of them is being exploited (CVE-2021-43226); 1 on CISA KEV. Patch Radar priority: Patch now. - Web page: https://patchblox.com/security/fix/microsoft/kb5008218 - Platform: Microsoft - Released: Dec 14, 2021 - Priority: Patch now (Closes CVE-2021-43226, exploited (CISA KEV, ransomware)) - CVEs: 28, exploited: 1, on CISA KEV: 1 - Vendor advisory: https://support.microsoft.com/help/5008218 ## Applies to | Product | Release | Fixed in | |---|---|---| | [Windows 10 Version 1809 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1809-for-32-bit-systems.md) | | 17763.2366 | | [Windows 10 Version 1809 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1809-for-arm64-based-systems.md) | | 17763.2366 | | [Windows 10 Version 1809 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1809-for-x64-based-systems.md) | | 17763.2366 | | [Windows Server 2019](https://patchblox.com/security/data/product/microsoft/windows-server-2019.md) | | 17763.2366 | | [Windows Server 2019 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2019-server-core-installation.md) | | 17763.2366 | ## CVEs this fix closes | CVE | Priority | Component | CVSS | EPSS | Exploitation | |---|---|---|---:|---:|---| | [CVE-2021-43226](https://patchblox.com/security/data/cve/CVE-2021-43226.md) | Patch now | Windows Common Log File System Driver | 7.8 | 0.0328 | CISA KEV, Ransomware | | [CVE-2021-43883](https://patchblox.com/security/data/cve/CVE-2021-43883.md) | Urgent | Windows Installer | 7.8 | 0.1215 | Disclosed | | [CVE-2021-43217](https://patchblox.com/security/data/cve/CVE-2021-43217.md) | Urgent | Windows Encrypting File System (EFS) | 8.1 | 0.0652 | | | [CVE-2021-43215](https://patchblox.com/security/data/cve/CVE-2021-43215.md) | Urgent | Internet Storage Name Service | 9.8 | 0.0287 | More likely | | [CVE-2021-43233](https://patchblox.com/security/data/cve/CVE-2021-43233.md) | Urgent | Remote Desktop Client | 7.5 | 0.0236 | More likely | | [CVE-2021-41333](https://patchblox.com/security/data/cve/CVE-2021-41333.md) | Urgent | Windows Print Spooler Components | 7.8 | 0.0108 | Disclosed | | [CVE-2021-43207](https://patchblox.com/security/data/cve/CVE-2021-43207.md) | Urgent | Windows Common Log File System Driver | 7.8 | 0.0068 | More likely | | [CVE-2021-43893](https://patchblox.com/security/data/cve/CVE-2021-43893.md) | High | Windows Encrypting File System (EFS) | 7.5 | 0.0672 | Disclosed | | [CVE-2021-43228](https://patchblox.com/security/data/cve/CVE-2021-43228.md) | High | Windows SymCrypt | 7.5 | 0.0387 | | | [CVE-2021-43219](https://patchblox.com/security/data/cve/CVE-2021-43219.md) | High | Windows DirectX | 7.4 | 0.0387 | | | [CVE-2021-43222](https://patchblox.com/security/data/cve/CVE-2021-43222.md) | High | Windows Message Queuing | 7.5 | 0.0317 | | | [CVE-2021-43236](https://patchblox.com/security/data/cve/CVE-2021-43236.md) | High | Windows Message Queuing | 7.5 | 0.0317 | | | [CVE-2021-43232](https://patchblox.com/security/data/cve/CVE-2021-43232.md) | High | Windows Event Tracing | 7.8 | 0.0218 | | | [CVE-2021-43234](https://patchblox.com/security/data/cve/CVE-2021-43234.md) | High | Role: Windows Fax Service | 7.8 | 0.0218 | | | [CVE-2021-43229](https://patchblox.com/security/data/cve/CVE-2021-43229.md) | High | Windows NTFS | 7.8 | 0.0179 | | | [CVE-2021-43247](https://patchblox.com/security/data/cve/CVE-2021-43247.md) | High | Windows TCP/IP | 7.8 | 0.0092 | | | [CVE-2021-43238](https://patchblox.com/security/data/cve/CVE-2021-43238.md) | High | Windows Remote Access Connection Manager | 7.8 | 0.0091 | | | [CVE-2021-43231](https://patchblox.com/security/data/cve/CVE-2021-43231.md) | High | Windows NTFS | 7.8 | 0.0072 | | | [CVE-2021-43230](https://patchblox.com/security/data/cve/CVE-2021-43230.md) | High | Windows NTFS | 7.8 | 0.0057 | | | [CVE-2021-43223](https://patchblox.com/security/data/cve/CVE-2021-43223.md) | High | Windows Remote Access Connection Manager | 7.8 | 0.0054 | | | [CVE-2021-43248](https://patchblox.com/security/data/cve/CVE-2021-43248.md) | High | Microsoft Windows Codecs Library | 7.8 | 0.0054 | | | [CVE-2021-43224](https://patchblox.com/security/data/cve/CVE-2021-43224.md) | Routine | Windows Common Log File System Driver | 5.5 | 0.0393 | | | [CVE-2021-43216](https://patchblox.com/security/data/cve/CVE-2021-43216.md) | Routine | Microsoft Local Security Authority Server (lsasrv) | 6.5 | 0.0343 | | | [CVE-2021-24084](https://patchblox.com/security/data/cve/CVE-2021-24084.md) | Routine | Windows Mobile Device Management | 5.5 | 0.0275 | | | [CVE-2021-43244](https://patchblox.com/security/data/cve/CVE-2021-43244.md) | Routine | Windows Kernel | 6.5 | 0.0084 | | | [CVE-2021-43227](https://patchblox.com/security/data/cve/CVE-2021-43227.md) | Routine | Windows Storage Spaces Controller | 5.5 | 0.0079 | | | [CVE-2021-43235](https://patchblox.com/security/data/cve/CVE-2021-43235.md) | Routine | Windows Storage | 5.5 | 0.0079 | | | [CVE-2021-43246](https://patchblox.com/security/data/cve/CVE-2021-43246.md) | Routine | Role: Windows Hyper-V | 5.6 | 0.0077 | | --- Data as of 2026-11-07T18:46:35Z 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 Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data 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.