Is CVE-2021-36942 being actively exploited?

Yes. CVE-2021-36942 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on November 3, 2021.

What is the CVSS score for CVE-2021-36942?

CVE-2021-36942 has a CVSS 3.1 base score of 7.5 (HIGH).

CVE-2021-36942

HIGH · CVSS 7.5CISA KEV: actively exploitedEPSS 66.0%EU EUVD: exploited

Windows LSA Spoofing Vulnerability

Key facts

CVSS score: 7.5 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS score: 66.0% (99th percentile)
In CISA KEV: Yes, added November 3, 2021
In EU EUVD: Yes (EUVD-2021-23518)
Published: August 12, 2021
NVD last modified: August 10, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Microsoft Windows Local Security Authority (LSA) Spoofing Vulnerability

Added to the KEV catalog on November 3, 2021; federal remediation due November 17, 2021. Known to be used in ransomware campaigns.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-23518 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on August 10, 2026.

View on the EU Vulnerability Database

Affected products

microsoft / windows server 2004
microsoft / windows server 2008
microsoft / windows server 2008
microsoft / windows server 2012
microsoft / windows server 2012
microsoft / windows server 2016
microsoft / windows server 2019
microsoft / windows server 20h2

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

Microsoft Windows 10 version 2004 (May 2020 Update), Microsoft Windows Server version 2004 (May 2020 Update) and others - Microsoft Corporation - Common Criteria 2020-50-INF-3671 - active

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942(Patch, Vendor Advisory)
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36942(Patch, Vendor Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36942(US Government Resource)
https://www.kb.cert.org/vuls/id/405600(Exploit, Third Party Advisory, US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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