# KB5003646: June 2021 cumulative update for Windows 10 1809

KB5003646, released June 8, 2021, fixes 23 CVEs across 5 products. 6 of them are being exploited (CVE-2021-1675); 6 on CISA KEV. Patch Radar priority: Patch now.

- Web page: https://patchblox.com/security/fix/microsoft/kb5003646
- Platform: Microsoft
- Released: Jun 8, 2021
- Priority: Patch now (Closes CVE-2021-1675, exploited (CISA KEV, ransomware))
- CVEs: 23, exploited: 6, on CISA KEV: 6
- Vendor advisory: https://support.microsoft.com/help/5003646

## 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) |  | 17763.1999 |
| [Windows 10 Version 1809 for ARM64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1809-for-arm64-based-systems.md) |  | 17763.1999 |
| [Windows 10 Version 1809 for x64-based Systems](https://patchblox.com/security/data/product/microsoft/windows-10-version-1809-for-x64-based-systems.md) |  | 17763.1999 |
| [Windows Server 2019](https://patchblox.com/security/data/product/microsoft/windows-server-2019.md) |  | 17763.1999 |
| [Windows Server 2019 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2019-server-core-installation.md) |  | 17763.1999 |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2021-1675](https://patchblox.com/security/data/cve/CVE-2021-1675.md) | Patch now | Windows Print Spooler Components | 7.8 | 0.8531 | CISA KEV, Ransomware |
| [CVE-2021-31955](https://patchblox.com/security/data/cve/CVE-2021-31955.md) | Patch now | Windows Kernel | 5.5 | 0.8111 | CISA KEV |
| [CVE-2021-33742](https://patchblox.com/security/data/cve/CVE-2021-33742.md) | Patch now | Windows MSHTML Platform | 7.5 | 0.5941 | CISA KEV |
| [CVE-2021-31956](https://patchblox.com/security/data/cve/CVE-2021-31956.md) | Patch now | Windows NTFS | 7.8 | 0.2227 | CISA KEV |
| [CVE-2021-31199](https://patchblox.com/security/data/cve/CVE-2021-31199.md) | Patch now | Windows Cryptographic Services | 5.2 | 0.0298 | CISA KEV |
| [CVE-2021-31201](https://patchblox.com/security/data/cve/CVE-2021-31201.md) | Patch now | Windows Cryptographic Services | 5.2 | 0.0262 | CISA KEV |
| [CVE-2021-31959](https://patchblox.com/security/data/cve/CVE-2021-31959.md) | Urgent | Microsoft Scripting Engine | 6.4 | 0.0923 | More likely |
| [CVE-2021-31954](https://patchblox.com/security/data/cve/CVE-2021-31954.md) | Urgent | Windows Common Log File System Driver | 7.8 | 0.0107 | More likely |
| [CVE-2021-31952](https://patchblox.com/security/data/cve/CVE-2021-31952.md) | Urgent | Windows Kernel-Mode Drivers | 7.8 | 0.0081 | More likely |
| [CVE-2021-31951](https://patchblox.com/security/data/cve/CVE-2021-31951.md) | Urgent | Windows Kernel | 7.8 | 0.0068 | More likely |
| [CVE-2021-31974](https://patchblox.com/security/data/cve/CVE-2021-31974.md) | High | Windows Network File System | 7.5 | 0.0673 |  |
| [CVE-2021-31962](https://patchblox.com/security/data/cve/CVE-2021-31962.md) | High | Windows Kerberos | 9.4 | 0.0381 |  |
| [CVE-2021-31975](https://patchblox.com/security/data/cve/CVE-2021-31975.md) | High | Windows Network File System | 7.5 | 0.0366 |  |
| [CVE-2021-31976](https://patchblox.com/security/data/cve/CVE-2021-31976.md) | High | Windows Network File System | 7.5 | 0.0366 |  |
| [CVE-2021-31977](https://patchblox.com/security/data/cve/CVE-2021-31977.md) | High | Role: Windows Hyper-V | 8.6 | 0.0318 |  |
| [CVE-2021-31968](https://patchblox.com/security/data/cve/CVE-2021-31968.md) | High | Windows Remote Desktop | 7.5 | 0.0318 | Disclosed |
| [CVE-2021-31958](https://patchblox.com/security/data/cve/CVE-2021-31958.md) | High | Windows NTLM | 7.5 | 0.0256 |  |
| [CVE-2021-31969](https://patchblox.com/security/data/cve/CVE-2021-31969.md) | High | Windows Drivers | 7.8 | 0.0122 |  |
| [CVE-2021-31953](https://patchblox.com/security/data/cve/CVE-2021-31953.md) | High | Windows Filter Manager | 7.8 | 0.0055 |  |
| [CVE-2021-31973](https://patchblox.com/security/data/cve/CVE-2021-31973.md) | High | Windows Installer | 7.8 | 0.0055 |  |
| [CVE-2021-31971](https://patchblox.com/security/data/cve/CVE-2021-31971.md) | Routine | Windows HTML Platform | 6.8 | 0.0209 |  |
| [CVE-2021-31970](https://patchblox.com/security/data/cve/CVE-2021-31970.md) | Routine | Windows TCP/IP | 5.5 | 0.0086 |  |
| [CVE-2021-31972](https://patchblox.com/security/data/cve/CVE-2021-31972.md) | Routine | Windows Event Logging Service | 5.5 | 0.0076 |  |

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Data as of 2026-11-09T13:31:49Z 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

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