Sandbox Escape Vulnerability in Mozilla Firefox Products

CVE-2026-84121

What is CVE-2026-84121?

A use-after-free vulnerability was discovered in the DOM of Mozilla Firefox's security component, leading to potential sandbox escape issues. This flaw could allow attackers to execute arbitrary code or gain elevated privileges through malicious web content. Mozilla has addressed this vulnerability in Firefox versions 155 and subsequent updates, including Firefox ESR releases. Users are urged to upgrade to the latest versions for improved security and protection against exploitation.

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