Vulnerability · CVE-2021-38646
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
Published Sep 15, 2021 · catalog updated Aug 10, 2026 · Microsoft Office
Patch now
CVE-2021-38646 is in the CISA known-exploited catalog, due Apr 18, 2022. Confirm Microsoft Office against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- Severity
- High7.8
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 7.99%
- Remediation
- Remediation guidance
- Affected products
- cpe microsoft/365 apps · cpe microsoft/office · cpe microsoft/office 2016 · cpe microsoft/office 2019 · vendor Microsoft Office
Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe microsoft/365 appsversion unspecified
- cpe microsoft/office2013
- cpe microsoft/office 2016version unspecified
- cpe microsoft/office 2019version unspecified
- vendor Microsoft Officeversion unspecified
How to fix CVE-2021-38646
Recommended remediation
Apply updates per vendor instructions. CISA due date Apr 18, 2022.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2021-38646 is in the CISA known-exploited catalog, due Apr 18, 2022. Confirm Microsoft Office against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with 2013. Apply updates per vendor instructions.
What should an analyst verify?
No weakness class is stored. EPSS 7.99%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Sep 15, 2021 · Catalog
Detected
Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
Mar 28, 2022 · CISA KEV
Known exploited
Apply updates per vendor instructions.
Apr 18, 2022 · CISA KEV
Remediation due
Apply updates per vendor instructions.
Aug 10, 2026 · Catalog
Updated
Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
Sources
- CISA KEVConfirmed exploitationCVE-2021-38646
Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
cisa.gov - CVE.orgVulnerability recordCVE-2021-38646
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2021-38646
30-day exploitation probability 8.0%
first.org - NIST NVDVulnerability recordCVE-2021-38646
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2021-38646
Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
vulncheck.com
References
Freshness
Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.