CVE-2016-2821

CVE-2016-2821 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

Use-after-free vulnerability in the mozilla::dom::Element class in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2, when contenteditable mode is enabled, allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) by triggering deletion of DOM elements that were created in the editor.

Frequently asked questions

What is CVE-2016-2821?
Use-after-free vulnerability in the mozilla::dom::Element class in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2, when contenteditable mode is enabled, allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) by triggering deletion of DOM elements that were created in the editor.
How severe is CVE-2016-2821?
CVE-2016-2821 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-2821 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-2821?
CVE-2016-2821 primarily affects Mozilla Firefox. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-2821?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-2821 published?
CVE-2016-2821 was published on 2016-06-13 and last updated on 2026-06-17.

References

Affected products (11)

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