What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.8 v2.0)
• Exploited in the wild: yes — in CISA KEV since 2022-03-28
• EPSS: 8.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-09-15 · updated 2026-08-10

Description

Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability

Affected products

• Microsoft 365 Apps: all versions
• Microsoft Office: 2013-sp1
• Microsoft Office 2016: all versions
• Microsoft Office 2019: all versions
• Microsoft 365 Apps: from 16.0.1 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
• Microsoft Office 2013 Service Pack 1: from 15.0.0 before 5381.1000 — fixed in 5381.1000
• Microsoft Office: from 16.0.0 before 5215.1000 — fixed in 5215.1000

How to fix

Upgrade to a fixed version: Microsoft 365 Apps https://aka.ms/OfficeSecurityReleases; Microsoft Office 2013 Service Pack 1 5381.1000; Microsoft Office 5215.1000. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38646
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38646
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-38646

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