CVE-2026-92018

Sandbox escape in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.

  • Published Sep 15, 2026
  • CVSS 9.6 critical
  • 0.4% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-92018 at the National Vulnerability Database