CVE-2026-92021

Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox ESR 140.16 and Thunderbird 140.16.

  • Published Sep 15, 2026
  • CVSS 8.8 high
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-92021 at the National Vulnerability Database