HIGH CISA KEV
CVE-2021-42278
CVSS v3
7.5
HIGH
EPSS Score
73.3 %
exploit probability, as of 2026-10-19
CISA KEV
Yes
known exploited
Exploitation
—
SSVC status
Get an alert for each new CVE published for the software you run.
Set up CVE WatchFree account · no credit card
Affected and fixed versions
Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2021-42278 yet.
Description
Active Directory Domain Services Elevation of Privilege Vulnerability
CISA Known Exploited Vulnerability
- Date Added
- 2022-04-11
- Patch Due Date
- 2022-05-02
- Ransomware Use
- Known
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- Published
- 2021-11-10
- Last Modified
- 2026-08-19
Frequently asked questions
What is CVE-2021-42278?
Active Directory Domain Services Elevation of Privilege Vulnerability
Is CVE-2021-42278 actively exploited?
Yes. CVE-2021-42278 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-05-02.
What is the CVSS score for CVE-2021-42278?
CVE-2021-42278 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C.
Hear about the next vulnerability in your software
CVE Watch matches each new CVE to the vendors and products you list (vendor and product, not the version) and puts it in your alerts with its KEV and EPSS status.
Already have an account? Open CVE WatchNo credit card required · No monthly cap on website lookups · 250 API requests/month
Go further
- For a threat intelligence platform: malware, C2 and ransomware indicators over STIX/TAXII.
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? CVE Watch alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.