CVE-2026-12321
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JIT Miscompilation in Firefox JavaScript WebAssembly

Publication date: 2026-06-16

Last updated on: 2026-06-16

Assigner: Mozilla Corporation

Description
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

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Meta Information

Published
2026-06-16
Last Modified
2026-06-16
Generated
2026-07-06
AI Q&A
2026-06-16
EPSS Evaluated
2026-07-05
NVD
CVE-2026-12321
EUVD
EUVD-2026-37067

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
mozilla firefox to 152.0.0 (exc)
mozilla thunderbird to 152.0.0 (exc)

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-670 The code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated.

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Executive Summary

This vulnerability is a Just-In-Time (JIT) miscompilation issue in the JavaScript WebAssembly component of Firefox. It means that the JIT compiler incorrectly compiles WebAssembly code, which could lead to unexpected behavior or security issues. The problem was addressed and fixed in Firefox version 152.

Impact Analysis

A JIT miscompilation vulnerability in the WebAssembly component could potentially cause incorrect execution of code, which might be exploited to cause crashes, data corruption, or other unintended behavior in Firefox. However, specific impacts or exploit scenarios are not detailed in the provided information.

Compliance Impact

There is no information available regarding the impact of this vulnerability on compliance with standards such as GDPR or HIPAA.

Mitigation Strategies

The vulnerability was fixed in Firefox 152. To mitigate this vulnerability, you should update your Firefox browser to version 152 or later.

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