Microsoft Active Directory Domain Services Privilege Escalation Vulnerability
Microsoft Active Directory Domain Services contains an unspecified vulnerability that allows for privilege escalation.
- Vendor
- Microsoft
- Product
- Active Directory
- CVSS
- 7.5
- EPSS (exploit probability)
- 77.2%
- Status
- kevransomware use
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-42287 being exploited?
Yes. CISA added CVE-2021-42287 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. CISA marks it as known to be used in ransomware campaigns.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 77.2% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2021-42287 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft Active Directory CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2022-26923 Microsoft Active Directory Domain Services Privilege Escalation Vulnerability | [ HIGH ] | 8.8 | 83.5% | |
| CVE-2021-42278 Microsoft Active Directory Domain Services Privilege Escalation Vulnerabilityransomware use | [ HIGH ] | 7.5 | 73.3% |