CVE-2026-4702

CRITICAL

JIT miscompilation in the JavaScript Engine component

Title source: cna
STIX 2.1

Description

JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

References (5)

Scores

CVSS v3 9.8
EPSS 0.0003
EPSS Percentile 6.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-843
Status published
Products (10)
mozilla/firefox < 140.9.0
mozilla/firefox < 149.0
Mozilla/Firefox 140.9 - 140.*
Mozilla/Firefox 149
Mozilla/Firefox unspecified - 149
Mozilla/Firefox ESR unspecified - 140.9
Mozilla/Thunderbird 140.9 - 140.*
Mozilla/Thunderbird 149
Mozilla/Thunderbird unspecified - 140.9
Mozilla/Thunderbird unspecified - 149
Published Mar 24, 2026
Tracked Since Mar 24, 2026