CVE-2010-3971

CVE-2010-3971 is a critical-severity vulnerability in Microsoft Internet Explorer with a CVSS 2.0 base score of 9.3. Its EPSS exploit-prediction score of 82% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-399.

Key facts

Description

Use-after-free vulnerability in the CSharedStyleSheet::Notify function in the Cascading Style Sheets (CSS) parser in mshtml.dll, as used in Microsoft Internet Explorer 6 through 8 and other products, allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a self-referential @import rule in a stylesheet, aka "CSS Memory Corruption Vulnerability."

Frequently asked questions

What is CVE-2010-3971?
Use-after-free vulnerability in the CSharedStyleSheet::Notify function in the Cascading Style Sheets (CSS) parser in mshtml.dll, as used in Microsoft Internet Explorer 6 through 8 and other products, allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a self-referential @import rule in a stylesheet, aka "CSS Memory Corruption Vulnerability."
How severe is CVE-2010-3971?
CVE-2010-3971 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2010-3971 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 82% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2010-3971?
CVE-2010-3971 primarily affects Microsoft Internet Explorer. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2010-3971?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2010-3971 published?
CVE-2010-3971 was published on 2010-12-22 and last updated on 2026-06-16.

References

Affected products (2)

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