CVE-2010-3962
Microsoft Internet Explorer Uninitialized Memory Corruption Vulnerability
Microsoft Internet Explorer
Use-after-free vulnerability in Microsoft Internet Explorer 6, 7, and 8 allows remote attackers to execute arbitrary code via vectors related to Cascading Style Sheets (CSS) token sequences and the clip attribute, aka an "invalid flag reference" issue or "Uninitialized Memory Corruption Vulnerability," as exploited in the wild in November 2010.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 6 October 2025. US federal agencies were required to remediate it by 27 October 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 96.8%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2010-3962 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2010-3962.
What does CVE-2010-3962 affect?
CVE-2010-3962 affects Microsoft Internet Explorer. Use-after-free vulnerability in Microsoft Internet Explorer 6, 7, and 8 allows remote attackers to execute arbitrary code via vectors related to Cascading Style Sheets (CSS) token sequences and the clip attribute, aka an "invalid flag reference" issue or "Uninitialized Memory Corruption Vulnerability," as exploited in the wild in November 2010.
How severe is CVE-2010-3962?
CVE-2010-3962 is rated HIGH with a CVSS base score of 8.1. EPSS puts the probability of exploitation in the next 30 days at 96.8%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 27 October 2025.
How should organisations respond to CVE-2010-3962?
Apply the vendor patch for Microsoft Internet Explorer as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.