CVE-2026-100793: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Thunderbird 157 and Firefox 157.

Affected products

• Mozilla Firefox
• Mozilla Thunderbird

Published 2026-09-29. Last modified 2026-10-01.