CRITICAL · 9.1

CVE-2026-4716

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.

Vulnerability 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.

CVSS Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
MozillaFirefox< 140.9.0

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-4716?

CVE-2026-4716 is a vulnerability with a CVSS score of 9.1 (CRITICAL). 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.

How severe is CVE-2026-4716?

CVE-2026-4716 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-4716?

Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox.