CVE-2012-1946

CVE-2012-1946 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 9.3. 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 9.3)
• EPSS exploit prediction: 4% (90th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-399
• Affected product: Mozilla Firefox
• Published: 2012-06-05
• Last modified: 2026-06-16

Description

Use-after-free vulnerability in the nsINode::ReplaceOrInsertBefore function in Mozilla Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10 might allow remote attackers to execute arbitrary code via document changes involving replacement or insertion of a node.

Frequently asked questions

What is CVE-2012-1946?

Use-after-free vulnerability in the nsINode::ReplaceOrInsertBefore function in Mozilla Firefox 4.x through 12.0, Firefox ESR 10.x before 10.0.5, Thunderbird 5.0 through 12.0, Thunderbird ESR 10.x before 10.0.5, and SeaMonkey before 2.10 might allow remote attackers to execute arbitrary code via document changes involving replacement or insertion of a node.

How severe is CVE-2012-1946?

CVE-2012-1946 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2012-1946 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2012-1946?

CVE-2012-1946 primarily affects Mozilla Firefox. In total, 168 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2012-1946?

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-2012-1946 published?

CVE-2012-1946 was published on 2012-06-05 and last updated on 2026-06-16.

References

• http://lists.opensuse.org/opensuse-security-announce/2012-06/msg00012.html
• http://lists.opensuse.org/opensuse-security-announce/2012-06/msg00015.html
• http://rhn.redhat.com/errata/RHSA-2012-0710.html
• http://rhn.redhat.com/errata/RHSA-2012-0715.html
• http://secunia.com/advisories/49981
• http://www.mandriva.com/security/advisories?name=MDVSA-2012:088
• http://www.mozilla.org/security/announce/2012/mfsa2012-38.html
• https://bugzilla.mozilla.org/show_bug.cgi?id=750109
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17010

Affected products (168)

• cpe:2.3:a:mozilla:firefox:4.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta1:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta10:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta11:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta12:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta2:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta3:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta4:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta5:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta6:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta7:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta8:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0:beta9:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:4.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:5.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:5.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:6.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:6.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:6.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:7.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:7.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:8.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:8.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:9.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:9.0.1:*:*:*:*:*:*:*
• 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:11.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:12.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:12.0:beta6:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0:alpha:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0:beta:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.3:*:*:*:*:*:*:*

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