CVE-2021-38646VulnerabilityPublished 03/28/2022Updated 10/24/2026

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

Affects Microsoft OfficeSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 03/28/2022
KEV deadline: 04/18/2022
Ransomware: Used in ransomware campaigns
EPSS: 8.0% chance of exploitation in 30 days – higher than 94% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2021-38646 (opens in a new tab)

Description

CVE-2021-38646 is a high-severity remote code execution vulnerability in the Microsoft Office Access Connectivity Engine. This vulnerability has been exploited in the wild and is known to be used in ransomware campaigns. No specific affected versions or patch information is provided in the available data.

Summary

Microsoft Office Access Connectivity Engine contains an unspecified vulnerability identified as CVE-2021-38646 that allows remote code execution. The vulnerability has been exploited in the wild and is associated with ransomware campaigns. No detailed technical information or affected version ranges are provided in the source data.

Impact

Successful exploitation of this vulnerability allows remote attackers to execute arbitrary code on affected systems, potentially leading to full system compromise. The vulnerability has been actively exploited in the wild and leveraged in ransomware attacks, indicating a significant real-world threat.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no patch or official fix information is provided, organizations should monitor Microsoft security advisories for updates and apply any released patches promptly.

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 11:12:18 UTC

References

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