# KB4556400: May 2020 security update

KB4556400, released May 14, 2020, fixes 2 CVEs across 8 products. None of them is reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/fix/microsoft/kb4556400
- Platform: Microsoft
- Released: May 14, 2020
- Priority: Urgent (Closes CVE-2020-0605, rated Critical)
- CVEs: 2, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://support.microsoft.com/help/4556400

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Microsoft .NET Framework 3.5 on Windows Server 2012](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-3.5-on-windows-server-2012.md) |  |  |
| [Microsoft .NET Framework 3.5 on Windows Server 2012 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-3.5-on-windows-server-2012-server-core-installation.md) |  |  |
| [Microsoft .NET Framework 4.5.2 on Windows Server 2012](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-4.5.2-on-windows-server-2012.md) |  |  |
| [Microsoft .NET Framework 4.5.2 on Windows Server 2012 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-4.5.2-on-windows-server-2012-server-core-installation.md) |  |  |
| [Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-4.6-4.6.1-4.6.2-4.7-4.7.1-4.7.2-on-windows-server-2012.md) |  |  |
| [Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-4.6-4.6.1-4.6.2-4.7-4.7.1-4.7.2-on-windows-server-2012-server-core-installation.md) |  |  |
| [Microsoft .NET Framework 4.8 on Windows Server 2012](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-4.8-on-windows-server-2012.md) |  |  |
| [Microsoft .NET Framework 4.8 on Windows Server 2012 (Server Core installation)](https://patchblox.com/security/data/product/microsoft/microsoft-.net-framework-4.8-on-windows-server-2012-server-core-installation.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2020-0605](https://patchblox.com/security/data/cve/CVE-2020-0605.md) | Urgent | .NET Framework | n/a | 0.1840 |  |
| [CVE-2020-1108](https://patchblox.com/security/data/cve/CVE-2020-1108.md) | High | .NET Core | 7.5 | 0.0646 |  |

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Data as of 2026-11-07T12:40:37Z 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