CVE-2021-42287
Published 2021-11-10 · Updated 2026-08-19 · Source secure@microsoft.com
Summary
CVE-2021-42287 is a high-severity (CVSS 7.5) vulnerability in Microsoft Active Directory. CISA added it to the Known Exploited Vulnerabilities catalog on April 11, 2022, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by May 2, 2022. CISA also lists it as known to be used in ransomware campaigns, so it should be prioritised accordingly. Microsoft has 390 vulnerabilities in the KEV catalog, 117 of them linked to ransomware.
All 390 known-exploited Microsoft vulnerabilities →Description
Active Directory Domain Services Elevation of Privilege Vulnerability
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Microsoft — Active Directory
Name: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability
Date added: 2022-04-11 · Due: 2022-05-02
Required action: Apply updates per vendor instructions.

