CRITICALCVSS 9.6
CVE-2026-84121
CVE-2026-84121 updated by NVD
Summary
Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
References
Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.
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