# CVE-2021-38646: Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability

CVE-2021-38646 is fixed in 5 products on 1 platform, first by KB5001958, released September 14, 2021. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on March 28, 2022, with known ransomware use. Patch Radar priority: Patch now.

- Web page: https://patchblox.com/security/cve/CVE-2021-38646
- Priority: Patch now
- CVSS: 7.8 (Important)
- EPSS: 0.0799
- CISA KEV: listed Mar 28, 2022, federal due date Apr 18, 2022, known ransomware use
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Sep 14, 2021
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38646

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Microsoft Office 2013 RT Service Pack 1 |  | [KB5001958](https://patchblox.com/security/data/fix/microsoft/kb5001958.md) | Sep 14, 2021 |
| Microsoft | Microsoft Office 2013 Service Pack 1 (32-bit editions) |  | [KB5001958](https://patchblox.com/security/data/fix/microsoft/kb5001958.md) | Sep 14, 2021 |
| Microsoft | Microsoft Office 2013 Service Pack 1 (64-bit editions) |  | [KB5001958](https://patchblox.com/security/data/fix/microsoft/kb5001958.md) | Sep 14, 2021 |
| Microsoft | Microsoft Office 2016 (32-bit edition) |  | [KB5001997](https://patchblox.com/security/data/fix/microsoft/kb5001997.md) | Sep 14, 2021 |
| Microsoft | Microsoft Office 2016 (64-bit edition) |  | [KB5001997](https://patchblox.com/security/data/fix/microsoft/kb5001997.md) | Sep 14, 2021 |

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Data as of 2026-11-08T19:12:23Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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