Name: CVE-2026-4702: Access of Resource Using Incompatible Type
Creator: Rapid7
Published: 2026-03-24T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-4702, CVSS 9.8, EPSS 0.00674

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

CVSS Details

CVSS 3.1 Base Score: 9.8
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Alma_linux	—	Upgrade firefox-x11Upgrade thunderbirdUpgrade firefox	Mar 31, 2026	Mar 26, 2026
Amazon Linux Ami 2	—	Upgrade thunderbirdUpgrade firefox	May 20, 2026	May 20, 2026
Amazon_linux_2023	—	Upgrade firefox-debugsourceUpgrade firefoxUpgrade firefox-debuginfo	Apr 14, 2026	Mar 24, 2026
Debian	—	Upgrade firefox-esrUpgrade thunderbird	Mar 30, 2026	Mar 30, 2026
Freebsd	—	Upgrade firefoxUpgrade thunderbird	Mar 27, 2026	Mar 26, 2026
Mfsa2026 20	—	Upgrade to Mozilla Firefox version 149.0Upgrade to the latest version of Mozilla Firefox	Mar 27, 2026	Mar 24, 2026
Mfsa2026 22	—	Upgrade to Mozilla Firefox ESR version 140.9Upgrade to the latest version of Mozilla Firefox	Mar 27, 2026	Mar 24, 2026
Mozilla Thunderbird	—	Upgrade to the latest version of Mozilla ThunderbirdUpgrade to Mozilla Thunderbird version 140.9	Mar 27, 2026	Mar 24, 2026
Oracle_linux	—	Upgrade thunderbirdUpgrade firefoxUpgrade firefox-x11	Mar 30, 2026	Mar 24, 2026
Redhat_linux	—	Upgrade thunderbirdUpgrade firefox-x11Upgrade firefox-debugsourceUpgrade thunderbird-debuginfoUpgrade firefox-debuginfoUpgrade thunderbird-debugsourceUpgrade firefoxNo solution exists	Mar 27, 2026	Mar 24, 2026
Rocky_linux	—	Upgrade firefox-debugsourceUpgrade thunderbird-debuginfoUpgrade firefox-x11Upgrade firefox-debuginfoUpgrade thunderbird-debugsourceUpgrade thunderbirdUpgrade firefox	Apr 8, 2026	Apr 7, 2026
Suse	—	Upgrade MozillaFirefoxUpgrade MozillaThunderbird-translations-commonUpgrade MozillaFirefox-develUpgrade MozillaThunderbird-translations-otherUpgrade MozillaThunderbird-openpgp-librnpUpgrade MozillaFirefox-translations-otherUpgrade MozillaThunderbirdUpgrade mozillafirefox-branding-upstreamUpgrade MozillaFirefox-translations-common	Mar 30, 2026	Mar 27, 2026

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CVSS Details

Covered by Rapid7

Prioritise with Active Threat Intelligence