Undefined behavior 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: 9.8

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

Download CVE-2026-2771 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-521-cve-2026-2962/

https://dnacompany.com/poc-128-cve-2026-25722/

https://dnacompany.com/poc-329-cve-2026-2528/