CVE-2026-100793

Thunderbird: JIT miscompilation in the JavaScript Engine component

Mozilla Thunderbird

CVSS

6.5Medium

ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV

Exploit odds (EPSS)0.27%Chance of exploitation activity in the next 30 days, higher than 18% of CVEs. Scored 23 Oct 2026FIRST EPSS

Fixed inNone listedNo source names a fixed version. Check the vendor advisory below

Published29 Sep 2026Updated 1 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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

Text from CVE List