# CVE-2021-27053: Microsoft Excel Remote Code Execution Vulnerability

CVE-2021-27053 is fixed in 9 products on 1 platform, first by KB4504707, released March 16, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-27053
- Priority: High
- CVSS: 7.8 (Important)
- EPSS: 0.0458
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Mar 9, 2021
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-27053

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Excel 2010 Service Pack 2 (32-bit editions) |  | [KB4504707](https://patchblox.com/security/data/fix/microsoft/kb4504707.md) | Mar 16, 2021 |
| Microsoft | Microsoft Excel 2010 Service Pack 2 (64-bit editions) |  | [KB4504707](https://patchblox.com/security/data/fix/microsoft/kb4504707.md) | Mar 16, 2021 |
| Microsoft | Microsoft Excel 2013 RT Service Pack 1 |  | [KB4493239](https://patchblox.com/security/data/fix/microsoft/kb4493239.md) | Mar 16, 2021 |
| Microsoft | Microsoft Excel 2013 Service Pack 1 (32-bit editions) |  | [KB4493239](https://patchblox.com/security/data/fix/microsoft/kb4493239.md) | Mar 16, 2021 |
| Microsoft | Microsoft Excel 2013 Service Pack 1 (64-bit editions) |  | [KB4493239](https://patchblox.com/security/data/fix/microsoft/kb4493239.md) | Mar 16, 2021 |
| Microsoft | Microsoft Excel 2016 (32-bit edition) |  | [KB4493233](https://patchblox.com/security/data/fix/microsoft/kb4493233.md) | Mar 16, 2021 |
| Microsoft | Microsoft Excel 2016 (64-bit edition) |  | [KB4493233](https://patchblox.com/security/data/fix/microsoft/kb4493233.md) | Mar 16, 2021 |
| Microsoft | Microsoft Office Online Server |  | [KB4493229](https://patchblox.com/security/data/fix/microsoft/kb4493229.md) | Mar 16, 2021 |
| Microsoft | Microsoft Office Web Apps Server 2013 Service Pack 1 |  | [KB4493234](https://patchblox.com/security/data/fix/microsoft/kb4493234.md) | Mar 16, 2021 |

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Data as of 2026-11-09T19:38:12Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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