# KB4577671: October 2020 cumulative update for Windows 10 1903 KB4577671, released October 13, 2020, fixes 50 CVEs across 8 products. None of them is reported as exploited. Patch Radar priority: Urgent. The product is no longer supported. - Web page: https://patchblox.com/security/fix/microsoft/kb4577671 - Platform: Microsoft - Released: Oct 13, 2020 - Priority: Urgent (Closes CVE-2020-16899, exploitation more likely) - CVEs: 50, exploited: 0, on CISA KEV: 0 - Vendor advisory: https://support.microsoft.com/help/4577671 ## Applies to | Product | Release | Fixed in | |---|---|---| | [Windows 10 Version 1903 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1903-for-32-bit-systems.md) | | | | [Windows 10 Version 1903 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1903-for-arm64-based-systems.md) | | | | [Windows 10 Version 1903 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1903-for-x64-based-systems.md) | | | | [Windows 10 Version 1909 for 32-bit Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1909-for-32-bit-systems.md) | | | | [Windows 10 Version 1909 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1909-for-arm64-based-systems.md) | | | | [Windows 10 Version 1909 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1909-for-x64-based-systems.md) | | | | [Windows Server, version 1903 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-version-1903-server-core-installation.md) | | | | [Windows Server, version 1909 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-version-1909-server-core-installation.md) | | | ## CVEs this fix closes | CVE | Priority | Component | CVSS | EPSS | Exploitation | |---|---|---|---:|---:|---| | [CVE-2020-16899](https://patchblox.com/security/data/cve/CVE-2020-16899.md) | Urgent | Microsoft Windows | 7.5 | 0.1345 | More likely | | [CVE-2020-16896](https://patchblox.com/security/data/cve/CVE-2020-16896.md) | Urgent | Windows RDP | 7.5 | 0.1260 | More likely | | [CVE-2020-16898](https://patchblox.com/security/data/cve/CVE-2020-16898.md) | Urgent | Microsoft Windows | 8.8 | 0.1094 | | | [CVE-2020-16915](https://patchblox.com/security/data/cve/CVE-2020-16915.md) | Urgent | Windows Media Player | 7.8 | 0.0984 | | | [CVE-2020-16968](https://patchblox.com/security/data/cve/CVE-2020-16968.md) | Urgent | Microsoft Windows Codecs Library | 7.8 | 0.0487 | | | [CVE-2020-16911](https://patchblox.com/security/data/cve/CVE-2020-16911.md) | Urgent | Microsoft Graphics Component | 8.8 | 0.0445 | | | [CVE-2020-16967](https://patchblox.com/security/data/cve/CVE-2020-16967.md) | Urgent | Microsoft Windows Codecs Library | 7.8 | 0.0421 | | | [CVE-2020-16923](https://patchblox.com/security/data/cve/CVE-2020-16923.md) | Urgent | Microsoft Graphics Component | 7.8 | 0.0383 | | | [CVE-2020-16907](https://patchblox.com/security/data/cve/CVE-2020-16907.md) | Urgent | Microsoft Windows | 7.8 | 0.0100 | More likely | | [CVE-2020-16913](https://patchblox.com/security/data/cve/CVE-2020-16913.md) | Urgent | Windows Kernel | 7.8 | 0.0100 | More likely | | [CVE-2020-16891](https://patchblox.com/security/data/cve/CVE-2020-16891.md) | Urgent | Windows Hyper-V | 8.8 | 0.0095 | | | [CVE-2020-16922](https://patchblox.com/security/data/cve/CVE-2020-16922.md) | Urgent | Microsoft Windows | 5.3 | 0.0081 | More likely | | [CVE-2020-16927](https://patchblox.com/security/data/cve/CVE-2020-16927.md) | High | Windows RDP | 7.5 | 0.0592 | | | [CVE-2020-1167](https://patchblox.com/security/data/cve/CVE-2020-1167.md) | High | Microsoft Graphics Component | 7.8 | 0.0472 | | | [CVE-2020-16924](https://patchblox.com/security/data/cve/CVE-2020-16924.md) | High | Microsoft Windows | 7.8 | 0.0412 | | | [CVE-2020-16939](https://patchblox.com/security/data/cve/CVE-2020-16939.md) | High | Group Policy | 7.8 | 0.0242 | | | [CVE-2020-16940](https://patchblox.com/security/data/cve/CVE-2020-16940.md) | High | Microsoft Windows | 7.8 | 0.0155 | | | [CVE-2020-16920](https://patchblox.com/security/data/cve/CVE-2020-16920.md) | High | Microsoft Windows | 7.8 | 0.0142 | | | [CVE-2020-16895](https://patchblox.com/security/data/cve/CVE-2020-16895.md) | High | Microsoft Windows | 7.8 | 0.0103 | | | [CVE-2020-16885](https://patchblox.com/security/data/cve/CVE-2020-16885.md) | High | Microsoft Windows | 7.8 | 0.0102 | Disclosed | | [CVE-2020-16935](https://patchblox.com/security/data/cve/CVE-2020-16935.md) | High | Microsoft Windows | 7.8 | 0.0100 | | | [CVE-2020-16890](https://patchblox.com/security/data/cve/CVE-2020-16890.md) | High | Windows Secure Kernel Mode | 7.8 | 0.0100 | | | [CVE-2020-16916](https://patchblox.com/security/data/cve/CVE-2020-16916.md) | High | Windows COM | 7.8 | 0.0098 | | | [CVE-2020-0764](https://patchblox.com/security/data/cve/CVE-2020-0764.md) | High | Microsoft Windows | 7.8 | 0.0096 | | | [CVE-2020-16877](https://patchblox.com/security/data/cve/CVE-2020-16877.md) | High | Microsoft Windows | 7.1 | 0.0096 | | | [CVE-2020-16902](https://patchblox.com/security/data/cve/CVE-2020-16902.md) | High | Windows Installer | 7.8 | 0.0094 | | | [CVE-2020-16976](https://patchblox.com/security/data/cve/CVE-2020-16976.md) | High | Microsoft Windows | 7.8 | 0.0093 | | | [CVE-2020-16876](https://patchblox.com/security/data/cve/CVE-2020-16876.md) | High | Microsoft Windows | 7.1 | 0.0092 | | | [CVE-2020-16887](https://patchblox.com/security/data/cve/CVE-2020-16887.md) | High | Microsoft Windows | 7.8 | 0.0092 | | | [CVE-2020-16892](https://patchblox.com/security/data/cve/CVE-2020-16892.md) | High | Windows Kernel | 7.8 | 0.0091 | | | [CVE-2020-16912](https://patchblox.com/security/data/cve/CVE-2020-16912.md) | High | Microsoft Windows | 7.8 | 0.0091 | | | [CVE-2020-16972](https://patchblox.com/security/data/cve/CVE-2020-16972.md) | High | Microsoft Windows | 7.8 | 0.0091 | | | [CVE-2020-16974](https://patchblox.com/security/data/cve/CVE-2020-16974.md) | High | Microsoft Windows | 7.8 | 0.0091 | | | [CVE-2020-16975](https://patchblox.com/security/data/cve/CVE-2020-16975.md) | High | Microsoft Windows | 7.8 | 0.0091 | | | [CVE-2020-1243](https://patchblox.com/security/data/cve/CVE-2020-1243.md) | High | Windows Hyper-V | 7.8 | 0.0090 | | | [CVE-2020-16936](https://patchblox.com/security/data/cve/CVE-2020-16936.md) | High | Microsoft Windows | 7.8 | 0.0090 | | | [CVE-2020-16980](https://patchblox.com/security/data/cve/CVE-2020-16980.md) | High | Microsoft Windows | 7.8 | 0.0090 | | | [CVE-2020-1080](https://patchblox.com/security/data/cve/CVE-2020-1080.md) | High | Microsoft Windows | 8.8 | 0.0089 | | | [CVE-2020-1047](https://patchblox.com/security/data/cve/CVE-2020-1047.md) | High | Windows Kernel | 7.8 | 0.0089 | | | [CVE-2020-16909](https://patchblox.com/security/data/cve/CVE-2020-16909.md) | High | Microsoft Windows | 7.8 | 0.0087 | Disclosed | | [CVE-2020-16973](https://patchblox.com/security/data/cve/CVE-2020-16973.md) | High | Microsoft Windows | 7.8 | 0.0087 | | | [CVE-2020-16900](https://patchblox.com/security/data/cve/CVE-2020-16900.md) | High | Microsoft Windows | 7.0 | 0.0071 | | | [CVE-2020-16910](https://patchblox.com/security/data/cve/CVE-2020-16910.md) | Routine | Windows Kernel | 6.2 | 0.0279 | | | [CVE-2020-16901](https://patchblox.com/security/data/cve/CVE-2020-16901.md) | Routine | Microsoft Windows | 5.0 | 0.0146 | Disclosed | | [CVE-2020-16889](https://patchblox.com/security/data/cve/CVE-2020-16889.md) | Routine | Windows Kernel | 5.5 | 0.0136 | | | [CVE-2020-16914](https://patchblox.com/security/data/cve/CVE-2020-16914.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0136 | | | [CVE-2020-16919](https://patchblox.com/security/data/cve/CVE-2020-16919.md) | Routine | Microsoft Windows | 5.5 | 0.0125 | | | [CVE-2020-16921](https://patchblox.com/security/data/cve/CVE-2020-16921.md) | Routine | Microsoft Windows | 5.5 | 0.0125 | | | [CVE-2020-16897](https://patchblox.com/security/data/cve/CVE-2020-16897.md) | Routine | Microsoft Windows | 5.5 | 0.0124 | | | [CVE-2020-16905](https://patchblox.com/security/data/cve/CVE-2020-16905.md) | Routine | Windows Error Reporting | 6.8 | 0.0101 | | --- Data as of 2026-11-07T06:34:28Z 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