CVE-2021-33742

HIGHNVD 7.58.8▲

7.5

Windows MSHTML Platform Remote Code Execution Vulnerability

CVSS v3: 7.5
EG Score: 8.8(medium)
EPSS: 98.8%
KEV: ⚠ Exploited

Published

June 8, 2021

Last Modified

October 29, 2025

References (3)

secure@microsofthttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33742
af854a3a-2127-422b-91ae-364da2661108https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33742
134c704f-9b21-4f2e-91b3-4a467353bcc0https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-33742

Weakness Classification(3)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Microsoft MSRCCVE-2021-337422021-06-08
Windows MSHTML Platform Remote Code Execution Vulnerability

Data Freshness Timeline

(refreshed 4× in last 7d / 4× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-26 19:13 UTCkev_newly_listed
2026-05-26 15:17 UTCEG score recompute
2026-05-26 15:17 UTCVendor advisory
2026-05-26 15:17 UTCGHSA enrichment

Frequently asked(6)

What is CVE-2021-33742?

CVE-2021-33742 is a high vulnerability published on June 8, 2021. Windows MSHTML Platform Remote Code Execution Vulnerability

When was CVE-2021-33742 disclosed?

CVE-2021-33742 was first published in the National Vulnerability Database on June 8, 2021, with the most recent update on October 29, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-33742 actively exploited?

Yes. CISA added CVE-2021-33742 to the Known Exploited Vulnerabilities catalog on November 3, 2021, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

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

CVE-2021-33742 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 8.8.

Which products are affected by CVE-2021-33742?

CVE-2021-33742 affects Microsoft Windows. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2021-33742?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-33742, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-33742

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CVE-2021-33742

Published

Last Modified

References (3)

Weakness Classification(3)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-33742?

Same vendor

Same CWE

CVE-2021-33742

📅 Published

🔄 Last Modified

🔗 References (3)

Weakness Classification(3)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-33742?

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References (3)

Frequently asked(6)

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