How severe is CVE-2021-38646?

CVE-2021-38646 has a CVSS 3.1 base score of 7.8 (HIGH). EPSS estimates a 8.0% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-38646: Microsoft Office Access Connectivity Engine Remote

CISA Known Exploited Vulnerabilities

Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2022-03-28

Remediation due

2022-04-18

Ransomware

Known use

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-38646

Description

Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability

Severity

CVSS 3.1 · CNA7.8 HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Affected Products

Vendor	Product	Affected versions
Microsoft	Microsoft 365 Apps for Enterprise	16.0.1 to <https://aka.ms/OfficeSecurityReleases
Microsoft	Microsoft Office 2013 Service Pack 1	15.0.0 to <5381.1000
Microsoft	Microsoft Office 2016	16.0.0 to <5215.1000
Microsoft	Microsoft Office 2019	19.0.0 to <https://aka.ms/OfficeSecurityReleases

References

2 Links

Vendor advisories

Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability

Other references

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38646

Record Details

Published

2021-09-15

Last updated

2026-08-10

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.