High 7.5Known exploited (CISA KEV)Published Aug 12, 2021

CVE-2021-36942Windows LSA Spoofing Vulnerability

Updated under an hour ago (Oct 28, 2026, 1:23 AM ET)

Does this affect you?

It affects Microsoft Windows Server 2008 R2 Service Pack 1 and 12 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021, 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

Windows LSA Spoofing Vulnerability

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:F/RL:O/RC:C
Weakness (CWE): Not given
Known exploited: Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021; known ransomware useApply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 66.02% (percentile 99)
Assigned by: microsoft
NVD analysis: Analyzed
Record last updated: Aug 10, 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 6.1.7601.25685	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 6.1.7601.25685	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 6.0.6003.21192	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 6.0.6003.21192	CNA record
Microsoft Windows Server 2012 microsoft:windows_server_2012 (from the name)	from 6.2.9200.0 before 6.2.9200.23435	CNA record
Microsoft Windows Server 2012 R2 microsoft:windows_server_2012_r2 (from the name)	from 6.3.9600.0 before 6.3.9600.20094	CNA record
Microsoft Windows Server 2016 microsoft:windows_server_2016 (from the name)	from 10.0.14393.0 before 10.0.14393.4583	CNA record
Microsoft Windows Server 2019 microsoft:windows_server_2019 (from the name)	from 10.0.17763.0 before 10.0.17763.2114	CNA record
Microsoft Windows Server version 2004 microsoft:windows_server_version_2004 (from the name)	from 10.0.0 before 10.0.19041.1165	CNA record
Microsoft Windows Server version 20H2 microsoft:windows_server_version_20h2 (from the name)	from 10.0.0 before 10.0.19042.1165	CNA record
1–10 of 16

References

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942	vendor-advisory, patch
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942	patch, vendor-advisory
https://www.kb.cert.org/vuls/id/405600	exploit, third-party-advisory, us-government-resource
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36942	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.