Is CVE-2021-36955 in the CISA KEV catalog?

Yes. CVE-2021-36955 is on the CISA Known Exploited Vulnerabilities list, added 2021-11-03, and has known ransomware campaign use.

What is the CVSS severity of CVE-2021-36955?

CVE-2021-36955 has a CVSS v3 base score of 7.8 (HIGH).

What is the EPSS score for CVE-2021-36955?

CVE-2021-36955 has an EPSS score of 3.05% (86th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-36955

HIGHCISA KEVEPSS 86th pctl

7.8

CVSS v3

NVD

Description

Windows Common Log File System Driver Elevation of Privilege Vulnerability

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

3.05%probability of exploitation in 30 days

86thpercentile

Elevated risk: more likely to be exploited than 86% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability

Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.

Apply updates per vendor instructions.

Remediation due: 2021-11-17

Associated with ransomware campaigns

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-30.