How severe is CVE-2011-3647?

CVE-2011-3647 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2011-3647 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-3647?

CVE-2011-3647 primarily affects Mozilla Firefox. In total, 215 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-3647?

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-2011-3647 published?

CVE-2011-3647 was published on 2011-11-09 and last updated on 2026-06-16.

CVE-2011-3647

CVE-2011-3647 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-20.

Key facts

Severity: Critical (CVSS 2.0 base score 9.3)
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Mozilla Firefox
Published: 2011-11-09
Last modified: 2026-06-16

Description

The JSSubScriptLoader in Mozilla Firefox before 3.6.24 and Thunderbird before 3.1.6 does not properly handle XPCNativeWrappers during calls to the loadSubScript method in an add-on, which makes it easier for remote attackers to gain privileges via a crafted web site that leverages certain unwrapping behavior, a related issue to CVE-2011-3004.

Frequently asked questions

What is CVE-2011-3647?: The JSSubScriptLoader in Mozilla Firefox before 3.6.24 and Thunderbird before 3.1.6 does not properly handle XPCNativeWrappers during calls to the loadSubScript method in an add-on, which makes it easier for remote attackers to gain privileges via a crafted web site that leverages certain unwrapping behavior, a related issue to CVE-2011-3004.
How severe is CVE-2011-3647?: CVE-2011-3647 has a CVSS 2.0 base score of 9.3, rated critical severity.
Is CVE-2011-3647 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-3647?: CVE-2011-3647 primarily affects Mozilla Firefox. In total, 215 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-3647?: 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-2011-3647 published?: CVE-2011-3647 was published on 2011-11-09 and last updated on 2026-06-16.

References

Affected products (215)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.2:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.3:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.4:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.5:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.6:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.6.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.7:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.7.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.8:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.9:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.9:rc:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.9.1:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.9.2:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.9.3:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.10:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:0.10.1:*:*:*:*:*:*:*
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:*:*:*:*:*:*:*

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