CVE-2026-92066

Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.

• Published Sep 15, 2026
• CVSS 9.8 critical
• 0.6% chance of exploitation in the next 30 days (EPSS)
• A fix is available

CVE-2026-92066 at the National Vulnerability Database