Vulnerability · NVD

CVE-2026-4702

CVE-2026-4702, critical severity (CVSS 9.8): 1 tracked app concerned, all fixed or indeterminable on their current version.

Severity (CVSS): 9.8
Exploitation: 0.5 %
Tracked apps: 1
Still exposed: 0

Published on 2026-03-24

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

Attack vector : Network No privileges required No user interaction

Show raw CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS 0.47% exploit very unlikely percentile 39.1%

Tracked apps referencing this CVE

For each app: the affected range, the fixing version, and where the tracked app stands today.

Mozilla Firefox Windows winget:Mozilla.Firefox

Affected <140.9.0 Fixed in 140.9.0 Latest tracked 154.0.1 patched

Observed affected builds (127)

140.0.4 140.0.2 140.0.1 140.0 139.0.4 139.0.1 139.0 138.0.4 138.0.3 138.0.1 138.0 137.0.2 137.0.1 137.0 136.0.4 136.0.3 136.0.2 136.0.1 136.0 135.0.1 135.0 134.0.2 134.0.1 134.0 133.0.3 133.0 132.0.2 132.0.1 132.0 131.0.3 +97 · see history

Vulnerable CPE configurations (2)

Vendor	Product	Platform	Versions	CPE 2.3 URI
mozilla	firefox All platforms (wildcard)	All platforms (wildcard)	<140.9.0	cpe:2.3:a:mozilla:firefox:::::esr:::*
mozilla	firefox All platforms (wildcard)	All platforms (wildcard)	<149.0	cpe:2.3:a:mozilla:firefox:::::-:::*

View on NVD ↗ Advisory · www.mozilla.org