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01 Record

CVE-2021-33742

Windows MSHTML Platform Remote Code Execution Vulnerability

HighKEVPUBLISHEDCNA: microsoft
CNA base score7.5 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

02 Description

Windows MSHTML Platform Remote Code Execution Vulnerability

03 Exploitation and scoring

Exploitation
Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2021-11-03. Federal remediation due 2021-11-17.
SSVC decision
  • ExploitationactiveCISA reports credible evidence of active exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
59.40% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 99.0% of scored records. A rank, not a probability.
NVD base score
7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD analysis status
Analyzed. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2021-06-08 22:46Z5 YR AGO
Last updated
2025-10-21 23:25Z1 YR AGO
Reserved
2021-05-28
Assigning CNA
microsoft
Record state
PUBLISHED
Severity
High (CVSS 7.5)
CNA CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Weaknesses
Data version
5.1
Document digest
9f465d51fbdb9fb2ff3e109e37e12e1ddeba90f78304ea58f9e9cd2b7b9c65b2

05 Affected products

VendorProductVersionsPlatforms
MicrosoftWindows 10 Version 180910.0.0 to < 10.0.17763.199932-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows Server 201910.0.0 to < 10.0.17763.1999x64-based Systems
MicrosoftWindows 10 Version 190910.0.0 to < 10.0.18363.162132-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows 10 Version 21H110.0.0 to < 10.0.19043.1052x64-based Systems, ARM64-based Systems, 32-bit Systems
MicrosoftWindows 10 Version 200410.0.0 to < 10.0.19041.105232-bit Systems, ARM64-based Systems, x64-based Systems
MicrosoftWindows 10 Version 20H210.0.0 to < 10.0.19042.105232-bit Systems, ARM64-based Systems
MicrosoftWindows 10 Version 150710.0.0 to < 10.0.10240.1896732-bit Systems, x64-based Systems
MicrosoftWindows 10 Version 160710.0.0 to < 10.0.14393.446732-bit Systems, x64-based Systems
MicrosoftWindows Server 201610.0.0 to < 10.0.14393.4467x64-based Systems
MicrosoftWindows 76.1.0 to < 6.1.7601.25632, 6.1.0 to < publication32-bit Systems
MicrosoftWindows 7 Service Pack 16.1.0 to < 6.1.7601.25632, 6.1.0 to < publicationx64-based Systems
MicrosoftWindows 8.16.3.0 to < 6.3.9600.20045, 6.3.0 to < 1.0.0.032-bit Systems, x64-based Systems, ARM64-based Systems
MicrosoftWindows Server 2008 Service Pack 26.0.0 to < 6.0.6003.21137, 6.0.0 to < publication32-bit Systems
MicrosoftWindows Server 2008 Service Pack 26.0.0 to < 6.0.6003.21137, 6.0.0 to < publicationx64-based Systems
MicrosoftWindows Server 2008 R2 Service Pack 16.1.0 to < 6.1.7601.25632, 6.1.0 to < publicationx64-based Systems
MicrosoftWindows Server 20126.2.0 to < 6.2.9200.23372, 6.2.0 to < 1.0.0.0x64-based Systems
MicrosoftWindows Server 2012 R26.3.0 to < 6.3.9600.20045, 6.3.0 to < 1.0.0.0x64-based Systems

06 References