Microsoft MSHTML Remote Code Execution Vulnerability
Microsoft · MSHTML
CVSS 8.8
EPSS 97%
no public exploit indexed
ransomware
Fix deadline passed 17 November 2021
What it is
Microsoft MSHTML contains a unspecified vulnerability that allows for remote code execution.
Why we say that
- Linked by CISA to known ransomware campaigns
- EPSS puts exploitation in the next 30 days at 97%
- CISA's federal remediation deadline (2021-11-17) has passed
- Listed in the CISA Known Exploited Vulnerabilities catalogue
Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.
What to do
Apply updates per vendor instructions.
What it costs when this goes wrong
This is where UK enforcement meets the vulnerability record. This vulnerability is used in ransomware campaigns; here is what ransomware has cost UK organisations at the regulator.
- Advanced Computer Software Group Limited The Information Commissioner’s Office (ICO) has fined Advanced Computer Software Group Ltd (Advanced) £3.07m for security failings…
- Optionis Group Limited The data controller suffered a ransomware attack, which resulted in the exfiltration of personal data. A reprimand was issued in r…