CVE-2026-4716

Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component

CVSS 9.1 CRITICALEPSS 0.4%CWE-908

Vexday Risk Score

28Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 9.1EPSS 0.4%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

24 Mar 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

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

Affected products

Mozilla · Firefox Mozilla · Thunderbird

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References

https://bugzilla.mozilla.org/show_bug.cgi?id=2018592 https://www.mozilla.org/security/advisories/mfsa2026-20/https://www.mozilla.org/security/advisories/mfsa2026-22/https://www.mozilla.org/security/advisories/mfsa2026-23/https://www.mozilla.org/security/advisories/mfsa2026-24/