How severe is CVE-2015-7221?

CVE-2015-7221 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2015-7221 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-7221?

CVE-2015-7221 primarily affects Mozilla Firefox. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-7221?

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-2015-7221 published?

CVE-2015-7221 was published on 2015-12-16 and last updated on 2026-06-17.

CVE-2015-7221

CVE-2015-7221 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-119.

Key facts

Severity: Critical (CVSS 2.0 base score 10.0)
EPSS exploit prediction: 5% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Mozilla Firefox
Published: 2015-12-16
Last modified: 2026-06-17

Description

Buffer overflow in the nsDeque::GrowCapacity function in xpcom/glue/nsDeque.cpp in Mozilla Firefox before 43.0 might allow remote attackers to cause a denial of service or possibly have unspecified other impact by triggering a deque size change.

Frequently asked questions

What is CVE-2015-7221?: Buffer overflow in the nsDeque::GrowCapacity function in xpcom/glue/nsDeque.cpp in Mozilla Firefox before 43.0 might allow remote attackers to cause a denial of service or possibly have unspecified other impact by triggering a deque size change.
How severe is CVE-2015-7221?: CVE-2015-7221 has a CVSS 2.0 base score of 10.0, rated critical severity.
Is CVE-2015-7221 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-7221?: CVE-2015-7221 primarily affects Mozilla Firefox. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-7221?: 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-2015-7221 published?: CVE-2015-7221 was published on 2015-12-16 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*

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