CVE-2011-0055

CVE-2011-0055 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: 7% (94th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-399
• Affected product: Mozilla Firefox
• Published: 2011-03-02
• Last modified: 2026-06-16

Description

Use-after-free vulnerability in the JSON.stringify method in js3250.dll in Mozilla Firefox before 3.5.17 and 3.6.x before 3.6.14, and SeaMonkey before 2.0.12, might allow remote attackers to execute arbitrary code via unspecified vectors related to the js_HasOwnProperty function and garbage collection.

Frequently asked questions

What is CVE-2011-0055?

Use-after-free vulnerability in the JSON.stringify method in js3250.dll in Mozilla Firefox before 3.5.17 and 3.6.x before 3.6.14, and SeaMonkey before 2.0.12, might allow remote attackers to execute arbitrary code via unspecified vectors related to the js_HasOwnProperty function and garbage collection.

How severe is CVE-2011-0055?

CVE-2011-0055 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2011-0055 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-0055?

CVE-2011-0055 primarily affects Mozilla Firefox. In total, 157 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-0055?

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-2011-0055 published?

CVE-2011-0055 was published on 2011-03-02 and last updated on 2026-06-16.

References

• http://downloads.avaya.com/css/P8/documents/100133195
• http://www.mandriva.com/security/advisories?name=MDVSA-2011:041
• http://www.mozilla.org/security/announce/2011/mfsa2011-03.html
• http://www.securityfocus.com/archive/1/516802
• http://www.securityfocus.com/bid/46661
• http://www.zerodayinitiative.com/advisories/ZDI-11-103/
• https://bugzilla.mozilla.org/show_bug.cgi?id=616009
• https://bugzilla.mozilla.org/show_bug.cgi?id=619255
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14476

Affected products (157)

• cpe:2.3:a:mozilla:firefox:3.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.9:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.10:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.11:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.12:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:3.6.13:*:*:*:*:*:*:*
• 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:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0.9:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1:alpha:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1:beta:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.9:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.10:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.11:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.1.12:*:*:*:*:*:*:*

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