Sandbox escape in the DOM: Content Processes component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
https://www.mozilla.org/security/advisories/mfsa2026-109/
https://www.mozilla.org/security/advisories/mfsa2026-106/
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-98516
https://bugzilla.mozilla.org/show_bug.cgi?id=2068448
Source: Mitre, NVD
Published: 2026-10-13
Updated: 2026-10-15
Base Score: 10
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
Severity: Critical
Base Score: 9.6
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS: 0.00338