Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

Published: 2026-02-24

CVSS: 10.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Download CVE-2026-2778 POC (Proof-of-Concept) here:

Tip: Download official Tor Browser at https://www.torproject.org/download/ to access .onion links.

Check our portfolio:

https://dnacompany.com/poc-711-cve-2026-24445/

https://dnacompany.com/poc-562-cve-2026-2634/

https://dnacompany.com/poc-364-cve-2019-25362/

https://dnacompany.com/poc-628-cve-2026-27608/

https://dnacompany.com/poc-326-cve-2026-2521/