CVE-2021-40444Vulnerability
Microsoft MSHTML Remote Code Execution Vulnerability
Reported by 3 independent sources · first reported by Huntress · last reported
Last reported 19 months ago
Fix due 17 Nov 2021
Used by ransomware: knownCISA KEV catalogue
higher than 99% of CVEsFIRST EPSS, as of 16 Oct 2026
What the reports say
4 reports, newest first · the exact sentence from each-
GreyNoise Detects Active Exploitation of CVEs Mentioned in Black Basta’s Leaked Chat Logs“CVE-2021-40444”
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FORMBOOK Adopts CAB-less Approach“…ic Intelligence & Analytics team is tracking a new FORMBOOK information-stealing campaign leveraging the MSHTML remote code exploit (CVE-2021-40444).”
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Rapid Response: Microsoft Office RCE - “Follina” MSDT Attack“Much like CVE-2021-40444, this extends the severity of this threat by not just “single-click” to exploit, but potentially with a “zero-click” trigger.”
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Threat Advisory: Hackers Are Exploiting CVE-2021-40444“Threat Advisory: Hackers Are Exploiting CVE-2021-40444”
Indicators reported together
named in the same reportsAlso named with it: CVE-2022-30190, CVE-2017-11882, CVE-2017-0199, CVE-2023-38831, CVE-2023-36884, CVE-2017-5753, CVE-2020-1472, CVE-2022-27925, CVE-2021-26855, CVE-2023-20198, CVE-2024-21762, CVE-2022-41082, CVE-2023-23397, CVE-2024-3400, CVE-2021-44228, CVE-2024-1709, CVE-2024-1708, CVE-2023-4966, CVE-2021-42278, CVE-2021-42287
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