# KB5002055: December 2021 security update

KB5002055, released December 14, 2021, fixes 5 CVEs in Microsoft SharePoint Enterprise Server 2016. None of them is reported as exploited. Patch Radar priority: High. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/microsoft/kb5002055
- Platform: Microsoft
- Released: Dec 14, 2021
- Priority: High (Closes CVE-2021-42309, high severity)
- CVEs: 5, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://support.microsoft.com/help/5002055

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Microsoft SharePoint Enterprise Server 2016](https://patchblox.com/security/data/product/microsoft/microsoft-sharepoint-enterprise-server-2016.md) |  |  |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2021-42309](https://patchblox.com/security/data/cve/CVE-2021-42309.md) | High | Microsoft Office SharePoint | 8.8 | 0.0293 |  |
| [CVE-2021-42294](https://patchblox.com/security/data/cve/CVE-2021-42294.md) | High | Microsoft Office SharePoint | 7.2 | 0.0231 |  |
| [CVE-2021-43876](https://patchblox.com/security/data/cve/CVE-2021-43876.md) | High | Microsoft Office SharePoint | 8.8 | 0.0203 |  |
| [CVE-2021-42320](https://patchblox.com/security/data/cve/CVE-2021-42320.md) | High | Microsoft Office SharePoint | 8.0 | 0.0160 |  |
| [CVE-2021-43242](https://patchblox.com/security/data/cve/CVE-2021-43242.md) | High | Microsoft Office SharePoint | 7.6 | 0.0130 |  |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo