Use After Free in Microsoft Internet Explorer

CVE-2010-3962

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.

Vulnerability class: Use-After-Free

EPSS: 0.969 (99.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2010-3962?
CVE-2010-3962 is a high-severity vulnerability in Microsoft Internet Explorer, classified under Use After Free. CVSS score: 8.1/10. Published 2010-11-05.
How severe is CVE-2010-3962?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2010-3962 known to be exploited?
Yes. CVE-2010-3962 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-10-06), indicating it is being actively exploited. 3 public proof-of-concept repositories are indexed.