7.8

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

CVSS: 7.8v3.1HighKEVRansomwareAnalyzed
Published 15-09-2021Last modified 10-08-2026
Open JSON

Vulnerability summary

CVE-2021-38646 is a high (CVSS 7.8) vulnerability in Microsoft Office. It is known to be exploited: CISA lists it, first on 28-03-2022. It has been used in ransomware campaigns. EPSS estimates a 7.99% chance of exploitation in the next 30 days, higher than 94.7% of scored vulnerabilities.

Overall risk
90/100
0100
Critical · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
7.99%
0%100%
Low · 0.00 pp in 30 days
KEVListedCISA
RansomwareKnown useFlagged by CISA
Public exploits0No public exploits recorded

Timeline

  1. 15-09-2021
    PublishedVulnerability first disclosed.
  2. 28-03-2022
    Added to CISA KEVMicrosoft Office Access Connectivity Engine Remote Code Execution Vulnerability
  3. 18-04-2022
    CISA remediation dueApply updates per vendor instructions.
  4. 10-08-2026
    Last modifiedVulnerability information updated.

Description

Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

7.99%

Chance of exploitation in the next 30 days

Percentile

95%

Versus all other CVEs

30-day change

0.00 pp

From 7.99% on 19-09-2026

19-09-202619-10-2026
EPSS score
7.99%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
28-03-2022
Federal due date
18-04-2022
Ransomware

CISA required action

Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2021-38646

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Microsoft8 products

1 vendor · 8 products

References

3 links