CVE-2012-3964

CVE-2012-3964 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-399.

Key facts

• Severity: Critical (CVSS 2.0 base score 10.0)
• EPSS exploit prediction: 5% (92nd percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-399
• Affected product: Mozilla Firefox
• Published: 2012-08-29
• Last modified: 2026-06-16

Description

Use-after-free vulnerability in the gfxTextRun::GetUserData function in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.

Frequently asked questions

What is CVE-2012-3964?

Use-after-free vulnerability in the gfxTextRun::GetUserData function in Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.

How severe is CVE-2012-3964?

CVE-2012-3964 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2012-3964 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2012-3964?

CVE-2012-3964 primarily affects Mozilla Firefox. In total, 339 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2012-3964?

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-2012-3964 published?

CVE-2012-3964 was published on 2012-08-29 and last updated on 2026-06-16.

References

• http://lists.opensuse.org/opensuse-security-announce/2012-08/msg00028.html
• http://lists.opensuse.org/opensuse-security-announce/2012-09/msg00011.html
• http://lists.opensuse.org/opensuse-security-announce/2012-09/msg00014.html
• http://rhn.redhat.com/errata/RHSA-2012-1210.html
• http://rhn.redhat.com/errata/RHSA-2012-1211.html
• http://www.mozilla.org/security/announce/2012/mfsa2012-58.html
• http://www.securityfocus.com/bid/55322
• http://www.ubuntu.com/usn/USN-1548-1
• http://www.ubuntu.com/usn/USN-1548-2
• http://www.xerox.com/download/security/security-bulletin/16287-4d6b7b0c81f7b/cert_XRX13-003_v1.0.pdf
• https://bugzilla.mozilla.org/show_bug.cgi?id=756241
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16857

Affected products (339)

• cpe:2.3:a:mozilla:firefox:10.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:10.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:10.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:10.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:10.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:10.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:10.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird_esr:10.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0:preview_release:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.4.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:beta1:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:beta2:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.9:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.10:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.11:*:*:*:*:*:*:*

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• CVE-2015-0335 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
• CVE-2015-0333 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
• CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
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