CVE-2026-4702
Received Received - Intake
JIT Miscompilation in Firefox JavaScript Engine Causes Potential Exploits

Publication date: 2026-03-24

Last updated on: 2026-04-13

Assigner: Mozilla Corporation

Description
JIT miscompilation in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
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Meta Information
Published
2026-03-24
Last Modified
2026-04-13
Generated
2026-06-16
AI Q&A
2026-03-24
EPSS Evaluated
2026-06-14
NVD
CVE-2026-4702
EUVD
EUVD-2026-14821
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
mozilla firefox to 149.0 (exc)
mozilla firefox to 140.9.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-843 The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
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Executive Summary

This vulnerability is a Just-In-Time (JIT) miscompilation issue in the JavaScript Engine component of Firefox. It affects versions of Firefox earlier than 149 and Firefox ESR earlier than 140.9. JIT miscompilation means that the JavaScript engine may incorrectly compile code at runtime, potentially leading to unexpected behavior.

Impact Analysis

The impact of this vulnerability could include incorrect execution of JavaScript code within affected versions of Firefox, which might lead to security issues such as crashes, data corruption, or exploitation by attackers. However, specific impacts are not detailed in the provided information.

Compliance Impact

There is no information available regarding how this vulnerability affects compliance with common standards and regulations such as GDPR or HIPAA.

Detection Guidance

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