CVE-2021-38646
KEVRansomware UseMicrosoft Office Access Connectivity Engine Remote Code Execution Vulnerability
Description
Microsoft Office Access Connectivity Engine contains an unspecified vulnerability which can allow for remote code execution.
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
CVSS 3.1 vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HPublishedSep 15, 2021
Last modifiedAug 10, 2026
Added to KEVMar 28, 2022
Remediation dueApr 18, 2022
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38646PatchVendor Advisory
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-38646PatchVendor Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-38646US Government Resource
0 recent articles mention this CVE
80
Risk assessment · Critical
Actively exploited and used by ransomware crews. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1654 days
- Ransomware
- Used in known ransomware campaigns
- CVSS
- 7.8 HIGH
- EPSS (30-day exploit probability)
- 8.0% · top 5% of all CVEs
- Weakness
- NVD-CWE-noinfo
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
- 4.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.