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CVE-2026-4716

Critical

Description

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.

SeverityCritical
CVSS9.1
Exploit probability—
ProductMozilla Firefox
PublishedMar 24, 2026
First seenMar 24, 2026
Weakness typeCWE-908CWE-908

How to fix

Update
  • mozilla firefox140.9.0, 149.0 or later

Affected products

ProductAffected versionsFixed in
mozilla firefoxv < 140.9.0, v < 149.0140.9.0, 149.0

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