Is CVE-2021-33742 in the CISA KEV catalog?

Yes. CVE-2021-33742 is on the CISA Known Exploited Vulnerabilities list, added 2021-11-03.

What is the CVSS severity of CVE-2021-33742?

CVE-2021-33742 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2021-33742?

CVE-2021-33742 has an EPSS score of 59.14% (99th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-33742

HIGHCISA KEVEPSS 99th pctl

7.5

CVSS v3

NVD

Description

Windows MSHTML Platform Remote Code Execution Vulnerability

CWE-787Out-of-bounds Write

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

59.14%probability of exploitation in 30 days

99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

Microsoft Windows MSHTML Platform Remote Code Execution Vulnerability

Microsoft Windows MSHTML Platform contains an unspecified vulnerability that allows for remote code execution.

Apply updates per vendor instructions.

Remediation due: 2021-11-17

References

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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 2025-10-29.