# KB5003173: May 2021 cumulative update for Windows 10 2004 KB5003173, released May 11, 2021, fixes 25 CVEs across 12 products. One of them is being exploited (CVE-2021-31166); 1 on CISA KEV. Patch Radar priority: Patch now. The product is no longer supported. - Web page: https://patchblox.com/security/fix/microsoft/kb5003173 - Platform: Microsoft - Released: May 11, 2021 - Priority: Patch now (Closes CVE-2021-31166, exploited (CISA KEV)) - CVEs: 25, exploited: 1, on CISA KEV: 1 - Vendor advisory: https://support.microsoft.com/help/5003173 ## Applies to | Product | Release | Fixed in | |---|---|---| | [Internet Explorer 11 on Windows 10 Version 2004 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-10-version-2004-for-32-bit-systems.md) | | | | [Internet Explorer 11 on Windows 10 Version 2004 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-10-version-2004-for-arm64-based-systems.md) | | | | [Internet Explorer 11 on Windows 10 Version 2004 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-10-version-2004-for-x64-based-systems.md) | | | | [Internet Explorer 11 on Windows 10 Version 20H2 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-10-version-20h2-for-32-bit-systems.md) | | | | [Internet Explorer 11 on Windows 10 Version 20H2 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-10-version-20h2-for-arm64-based-systems.md) | | | | [Windows 10 Version 2004 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-2004-for-32-bit-systems.md) | | | | [Windows 10 Version 2004 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-2004-for-arm64-based-systems.md) | | | | [Windows 10 Version 2004 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-2004-for-x64-based-systems.md) | | | | [Windows 10 Version 20H2 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-20h2-for-32-bit-systems.md) | | | | [Windows 10 Version 20H2 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-20h2-for-arm64-based-systems.md) | | | | [Windows Server, version 2004 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-version-2004-server-core-installation.md) | | | | [Windows Server, version 20H2 (Server Core Installation)](https://patchblox.com/security/data/product/microsoft/windows-server-version-20h2-server-core-installation.md) | | | ## CVEs this fix closes | CVE | Priority | Component | CVSS | EPSS | Exploitation | |---|---|---|---:|---:|---| | [CVE-2021-31166](https://patchblox.com/security/data/cve/CVE-2021-31166.md) | Patch now | Windows HTTP.sys | 9.8 | 0.9987 | CISA KEV | | [CVE-2021-28476](https://patchblox.com/security/data/cve/CVE-2021-28476.md) | Urgent | Role: Windows Hyper-V | 9.9 | 0.3923 | | | [CVE-2021-26419](https://patchblox.com/security/data/cve/CVE-2021-26419.md) | Urgent | Internet Explorer | 6.4 | 0.2277 | More likely | | [CVE-2021-31194](https://patchblox.com/security/data/cve/CVE-2021-31194.md) | Urgent | Windows OLE | 8.8 | 0.0235 | | | [CVE-2021-31188](https://patchblox.com/security/data/cve/CVE-2021-31188.md) | Urgent | Microsoft Graphics Component | 7.8 | 0.0137 | More likely | | [CVE-2021-31170](https://patchblox.com/security/data/cve/CVE-2021-31170.md) | Urgent | Microsoft Graphics Component | 7.8 | 0.0101 | More likely | | [CVE-2021-31186](https://patchblox.com/security/data/cve/CVE-2021-31186.md) | High | Windows RDP Client | 7.4 | 0.0297 | | | [CVE-2021-31192](https://patchblox.com/security/data/cve/CVE-2021-31192.md) | High | Microsoft Windows Codecs Library | 7.8 | 0.0225 | | | [CVE-2021-28455](https://patchblox.com/security/data/cve/CVE-2021-28455.md) | High | Jet Red and Access Connectivity | 8.8 | 0.0212 | | | [CVE-2021-31187](https://patchblox.com/security/data/cve/CVE-2021-31187.md) | High | Windows WalletService | 7.8 | 0.0114 | | | [CVE-2021-31167](https://patchblox.com/security/data/cve/CVE-2021-31167.md) | High | Windows Container Manager Service | 7.8 | 0.0101 | | | [CVE-2021-31165](https://patchblox.com/security/data/cve/CVE-2021-31165.md) | High | Windows Container Manager Service | 7.8 | 0.0098 | | | [CVE-2021-31168](https://patchblox.com/security/data/cve/CVE-2021-31168.md) | High | Windows Container Manager Service | 7.8 | 0.0098 | | | [CVE-2021-31169](https://patchblox.com/security/data/cve/CVE-2021-31169.md) | High | Windows Container Manager Service | 7.8 | 0.0098 | | | [CVE-2021-31182](https://patchblox.com/security/data/cve/CVE-2021-31182.md) | High | Microsoft Bluetooth Driver | 7.1 | 0.0084 | | | [CVE-2021-31208](https://patchblox.com/security/data/cve/CVE-2021-31208.md) | High | Windows Container Manager Service | 7.8 | 0.0058 | | | [CVE-2021-31193](https://patchblox.com/security/data/cve/CVE-2021-31193.md) | High | Windows SSDP Service | 7.8 | 0.0052 | | | [CVE-2020-26144](https://patchblox.com/security/data/cve/CVE-2020-26144.md) | Routine | Windows Wireless Networking | 6.5 | 0.0491 | | | [CVE-2020-24588](https://patchblox.com/security/data/cve/CVE-2020-24588.md) | Routine | Windows Wireless Networking | 6.5 | 0.0361 | | | [CVE-2021-31205](https://patchblox.com/security/data/cve/CVE-2021-31205.md) | Routine | Windows SMB | 6.5 | 0.0291 | | | [CVE-2020-24587](https://patchblox.com/security/data/cve/CVE-2020-24587.md) | Routine | Windows Wireless Networking | 6.5 | 0.0259 | | | [CVE-2021-31184](https://patchblox.com/security/data/cve/CVE-2021-31184.md) | Routine | Microsoft Windows IrDA | 5.5 | 0.0156 | | | [CVE-2021-28479](https://patchblox.com/security/data/cve/CVE-2021-28479.md) | Routine | Windows CSC Service | 5.5 | 0.0076 | | | [CVE-2021-31191](https://patchblox.com/security/data/cve/CVE-2021-31191.md) | Routine | Windows Projected File System FS Filter | 5.5 | 0.0076 | | | [CVE-2021-31185](https://patchblox.com/security/data/cve/CVE-2021-31185.md) | Routine | Windows Desktop Bridge | 5.5 | 0.0065 | | --- Data as of 2026-11-07T18:46:35Z UTC. 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