CVE-2021-38646 kev+ ransomware in the critical feed json
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
published 2021-09-15 5 y ago modified 2026-08-10 2 mo ago also EUVD-2021-25085
- cvss
- 7.8
- version 3.1, CNA
- cisa kev
- Exploited
- added 2022-03-28, used in ransomware
- epss
- 8.0%
- EPSS 8.0% chance of exploitation in 30 days, percentile 94%
- public exploits
- 0
- none known
Summary
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
Patch / fix
cisa required action Apply updates per vendor instructions.
- Microsoft Microsoft Office 2013 Service Pack 1 5381.1000
- Microsoft Microsoft Office 2016 5215.1000
Timeline
- Published
- Added to CISA KEV
- CISA patch deadline
- CISA SSVC: exploitation active
Known exploited
- Added
- 4 y ago
- Patch by
- 2022-04-18 (4 y ago)
- Ransomware
- Known to be used in ransomware campaigns
- Required action
- Apply updates per vendor instructions.
- Vendor, product
- Microsoft, Office
- CISA name
- Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
CISA SSVC
- Exploitation
- Active, exploited in the wild
- Automatable
- no
- Technical impact
- total
- Assessed
- 21 mo ago
Exploit prediction
7.99% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.8 | 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 |
| CNA | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
Affected products
- Microsoft Microsoft 365 Apps for Enterprise
- Microsoft Microsoft Office 2013 Service Pack 1
- Microsoft Microsoft Office 2016
- Microsoft Microsoft Office 2019
References
-
msrc.microsoft.com
/update-guide/vulnerability/CVE-2021-38646
vendor-advisory, patch
-
portal.msrc.microsoft.com
/en-US/security-guidance/advisory/CVE-2021-38646
patch, vendor-advisory
-
cisa.gov
/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-38646
government-resource, us-government-resource
Sources
- CVE List CVE-2021-38646
- NVD CVE-2021-38646
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.