# KB4577066: September 2020 security update KB4577066, released September 8, 2020, fixes 49 CVEs across 9 products. One of them is being exploited (CVE-2020-0878); 1 on CISA KEV. Patch Radar priority: Patch now. - Web page: https://patchblox.com/security/fix/microsoft/kb4577066 - Platform: Microsoft - Released: Sep 8, 2020 - Priority: Patch now (Closes CVE-2020-0878, exploited (CISA KEV, ransomware)) - CVEs: 49, exploited: 1, on CISA KEV: 1 - Vendor advisory: https://support.microsoft.com/help/4577066 ## Applies to | Product | Release | Fixed in | |---|---|---| | [Internet Explorer 11 on Windows 8.1 for 32-bit systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-8.1-for-32-bit-systems.md) | | | | [Internet Explorer 11 on Windows 8.1 for x64-based systems](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-8.1-for-x64-based-systems.md) | | | | [Internet Explorer 11 on Windows RT 8.1](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-rt-8.1.md) | | | | [Internet Explorer 11 on Windows Server 2012 R2](https://patchblox.com/security/data/product/microsoft/internet-explorer-11-on-windows-server-2012-r2.md) | | | | [Windows 8.1 for 32-bit systems](https://patchblox.com/security/data/product/microsoft/windows-8.1-for-32-bit-systems.md) | | | | [Windows 8.1 for x64-based systems](https://patchblox.com/security/data/product/microsoft/windows-8.1-for-x64-based-systems.md) | | | | [Windows RT 8.1](https://patchblox.com/security/data/product/microsoft/windows-rt-8.1.md) | | | | [Windows Server 2012 R2](https://patchblox.com/security/data/product/microsoft/windows-server-2012-r2.md) | | | | [Windows Server 2012 R2 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2012-r2-server-core-installation.md) | | | ## CVEs this fix closes | CVE | Priority | Component | CVSS | EPSS | Exploitation | |---|---|---|---:|---:|---| | [CVE-2020-0878](https://patchblox.com/security/data/cve/CVE-2020-0878.md) | Patch now | Microsoft Browsers | 4.2 | 0.0270 | CISA KEV, Ransomware | | [CVE-2020-0922](https://patchblox.com/security/data/cve/CVE-2020-0922.md) | Urgent | Microsoft Windows | 8.8 | 0.0491 | | | [CVE-2020-0664](https://patchblox.com/security/data/cve/CVE-2020-0664.md) | Urgent | Windows Active Directory | 6.5 | 0.0400 | More likely | | [CVE-2020-1285](https://patchblox.com/security/data/cve/CVE-2020-1285.md) | Urgent | Microsoft Graphics Component | 8.4 | 0.0396 | | | [CVE-2020-0856](https://patchblox.com/security/data/cve/CVE-2020-0856.md) | Urgent | Windows Active Directory | 6.5 | 0.0390 | More likely | | [CVE-2020-1252](https://patchblox.com/security/data/cve/CVE-2020-1252.md) | Urgent | Microsoft Windows | 7.8 | 0.0388 | | | [CVE-2020-1508](https://patchblox.com/security/data/cve/CVE-2020-1508.md) | Urgent | Microsoft Windows | 7.6 | 0.0326 | | | [CVE-2020-1593](https://patchblox.com/security/data/cve/CVE-2020-1593.md) | Urgent | Microsoft Windows | 7.6 | 0.0282 | | | [CVE-2020-0941](https://patchblox.com/security/data/cve/CVE-2020-0941.md) | Urgent | Windows Kernel | 5.5 | 0.0113 | More likely | | [CVE-2020-1115](https://patchblox.com/security/data/cve/CVE-2020-1115.md) | Urgent | Windows Common Log File System Driver | 7.8 | 0.0109 | More likely | | [CVE-2020-1245](https://patchblox.com/security/data/cve/CVE-2020-1245.md) | Urgent | Microsoft Graphics Component | 7.0 | 0.0083 | More likely | | [CVE-2020-1152](https://patchblox.com/security/data/cve/CVE-2020-1152.md) | Urgent | Microsoft Graphics Component | 5.8 | 0.0060 | More likely | | [CVE-2020-1074](https://patchblox.com/security/data/cve/CVE-2020-1074.md) | High | Microsoft JET Database Engine | 7.8 | 0.4603 | | | [CVE-2020-1013](https://patchblox.com/security/data/cve/CVE-2020-1013.md) | High | Microsoft Windows | 7.5 | 0.0646 | | | [CVE-2020-1031](https://patchblox.com/security/data/cve/CVE-2020-1031.md) | High | Windows DHCP Server | 7.5 | 0.0514 | | | [CVE-2020-0836](https://patchblox.com/security/data/cve/CVE-2020-0836.md) | High | Microsoft Windows DNS | 7.5 | 0.0505 | | | [CVE-2020-1228](https://patchblox.com/security/data/cve/CVE-2020-1228.md) | High | Microsoft Windows DNS | 7.5 | 0.0450 | | | [CVE-2020-1039](https://patchblox.com/security/data/cve/CVE-2020-1039.md) | High | Microsoft JET Database Engine | 7.8 | 0.0427 | | | [CVE-2020-1012](https://patchblox.com/security/data/cve/CVE-2020-1012.md) | High | Internet Explorer | 8.8 | 0.0374 | | | [CVE-2020-0718](https://patchblox.com/security/data/cve/CVE-2020-0718.md) | High | Windows Active Directory | 8.8 | 0.0361 | | | [CVE-2020-0761](https://patchblox.com/security/data/cve/CVE-2020-0761.md) | High | Windows Active Directory | 8.8 | 0.0361 | | | [CVE-2020-17162](https://patchblox.com/security/data/cve/CVE-2020-17162.md) | High | Microsoft Windows | 8.8 | 0.0243 | | | [CVE-2020-0886](https://patchblox.com/security/data/cve/CVE-2020-0886.md) | High | Microsoft Windows | 7.8 | 0.0124 | | | [CVE-2020-1030](https://patchblox.com/security/data/cve/CVE-2020-1030.md) | High | Windows Print Spooler Components | 7.8 | 0.0110 | | | [CVE-2020-0911](https://patchblox.com/security/data/cve/CVE-2020-0911.md) | High | Microsoft Windows | 7.8 | 0.0104 | | | [CVE-2020-0782](https://patchblox.com/security/data/cve/CVE-2020-0782.md) | High | Microsoft Windows | 7.8 | 0.0100 | | | [CVE-2020-0838](https://patchblox.com/security/data/cve/CVE-2020-0838.md) | High | Windows NTFS | 7.8 | 0.0100 | | | [CVE-2020-0998](https://patchblox.com/security/data/cve/CVE-2020-0998.md) | High | Microsoft Graphics Component | 7.8 | 0.0100 | | | [CVE-2020-0648](https://patchblox.com/security/data/cve/CVE-2020-0648.md) | High | Microsoft Windows | 7.8 | 0.0097 | | | [CVE-2020-0790](https://patchblox.com/security/data/cve/CVE-2020-0790.md) | High | Microsoft Windows | 7.8 | 0.0093 | | | [CVE-2020-1052](https://patchblox.com/security/data/cve/CVE-2020-1052.md) | High | Microsoft Windows | 7.8 | 0.0093 | | | [CVE-2020-1376](https://patchblox.com/security/data/cve/CVE-2020-1376.md) | High | Microsoft Windows | 7.8 | 0.0093 | | | [CVE-2020-1491](https://patchblox.com/security/data/cve/CVE-2020-1491.md) | High | Microsoft Windows | 7.8 | 0.0093 | | | [CVE-2020-1559](https://patchblox.com/security/data/cve/CVE-2020-1559.md) | High | Microsoft Windows | 7.8 | 0.0093 | | | [CVE-2020-0912](https://patchblox.com/security/data/cve/CVE-2020-0912.md) | High | Microsoft Windows | 7.0 | 0.0078 | | | [CVE-2020-1034](https://patchblox.com/security/data/cve/CVE-2020-1034.md) | Routine | Windows Kernel | 6.8 | 0.0485 | | | [CVE-2020-1256](https://patchblox.com/security/data/cve/CVE-2020-1256.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0460 | | | [CVE-2020-1097](https://patchblox.com/security/data/cve/CVE-2020-1097.md) | Routine | Microsoft Graphics Component | 6.5 | 0.0459 | | | [CVE-2020-1091](https://patchblox.com/security/data/cve/CVE-2020-1091.md) | Routine | Microsoft Graphics Component | 6.5 | 0.0448 | | | [CVE-2020-0875](https://patchblox.com/security/data/cve/CVE-2020-0875.md) | Routine | Microsoft Windows | 5.5 | 0.0444 | | | [CVE-2020-1589](https://patchblox.com/security/data/cve/CVE-2020-1589.md) | Routine | Windows Kernel | 4.4 | 0.0131 | | | [CVE-2020-1038](https://patchblox.com/security/data/cve/CVE-2020-1038.md) | Routine | Microsoft Windows | 5.5 | 0.0122 | | | [CVE-2020-16854](https://patchblox.com/security/data/cve/CVE-2020-16854.md) | Routine | Windows Kernel | 5.5 | 0.0121 | | | [CVE-2020-1033](https://patchblox.com/security/data/cve/CVE-2020-1033.md) | Routine | Windows Kernel | 4.0 | 0.0116 | | | [CVE-2020-0921](https://patchblox.com/security/data/cve/CVE-2020-0921.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0108 | | | [CVE-2020-1083](https://patchblox.com/security/data/cve/CVE-2020-1083.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0108 | | | [CVE-2020-1250](https://patchblox.com/security/data/cve/CVE-2020-1250.md) | Routine | Microsoft Graphics Component | 5.5 | 0.0108 | | | [CVE-2020-1598](https://patchblox.com/security/data/cve/CVE-2020-1598.md) | Routine | Microsoft Windows | 4.6 | 0.0093 | | | [CVE-2020-1596](https://patchblox.com/security/data/cve/CVE-2020-1596.md) | Routine | Microsoft Windows | 5.4 | 0.0089 | | --- Data as of 2026-11-07T18:46:35Z UTC. 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