High 7.5Known exploited (CISA KEV)Published Nov 9, 2021

CVE-2021-42287Active Directory Domain Services Elevation of Privilege Vulnerability

Updated under an hour ago (Oct 27, 2026, 1:00 PM ET)

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It affects Microsoft Windows Server 2008 R2 Service Pack 1 and 13 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Apr 11, 2022; federal agencies had to remediate by May 2, 2022, and it is known to be used in ransomware. Treat that date as your deadline.

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Every CVE for Microsoft Windows Server 2008 R2 Service Pack 1

Exploited in the last 30 days

Active Directory Domain Services Elevation of Privilege Vulnerability

CVSS: 7.5 HIGH (v3.1, CNA)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
Weakness (CWE): Not given
Known exploited: Added to CISA KEV Apr 11, 2022; federal remediation due May 2, 2022; known ransomware useApply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 77.17% (percentile 100)
Assigned by: microsoft
NVD analysis: Analyzed
Record last updated: Aug 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Microsoft Windows Server 2008 R2 Service Pack 1 microsoft:windows_server_2008_r2_service_pack_1 (from the name)	from 6.1.7601.0 before 6.1.7601.25769	CNA record
Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation) microsoft:windows_server_2008_r2_service_pack_1_server_core_installation (from the name)	from 6.1.7601.0 before 6.1.7601.25769	CNA record
Microsoft Windows Server 2008 Service Pack 2 microsoft:windows_server_2008_service_pack_2 (from the name)	from 6.0.6003.0 before 6.0.6003.21282	CNA record
Microsoft Windows Server 2008 Service Pack 2 (Server Core installation) microsoft:windows_server_2008_service_pack_2_server_core_installation (from the name)	from 6.0.6003.0 before 6.0.6003.21282	CNA record
Microsoft Windows Server 2012 microsoft:windows_server_2012 (from the name)	from 6.2.9200.0 before 6.2.9200.23517	CNA record
Microsoft Windows Server 2012 R2 microsoft:windows_server_2012_r2 (from the name)	from 6.3.9600.0 before 6.3.9600.20174	CNA record
Microsoft Windows Server 2016 microsoft:windows_server_2016 (from the name)	from 10.0.14393.0 before 10.0.14393.4770	CNA record
Microsoft Windows Server 2019 microsoft:windows_server_2019 (from the name)	from 10.0.17763.0 before 10.0.17763.2300	CNA record
Microsoft Windows Server 2022 microsoft:windows_server_2022 (from the name)	from 10.0.20348.0 before 10.0.20348.350	CNA record
Microsoft Windows Server version 2004 microsoft:windows_server_version_2004 (from the name)	from 10.0.0 before 10.0.19041.1348	CNA record
1–10 of 18

References

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42287	vendor-advisory, patch
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42287	patch, vendor-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42287	us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.