JIT Miscompilation Vulnerability in Firefox WebAssembly Component
CVE-2026-12321

Currently unrated

Key Information:

Vendor: Mozilla
Status: Firefox
Vendor: CVE Published:; 16 June 2026

What is CVE-2026-12321?

This vulnerability occurs in the JavaScript: WebAssembly component of Firefox, where improper Just-In-Time (JIT) compilation can lead to unexpected behaviors or potential exploitation. Mozilla has addressed this vulnerability in Firefox version 152, ensuring that users are protected against possible attacks that could exploit this miscompilation. Keeping Firefox updated is crucial for maintaining security against such vulnerabilities.

Affected Version(s)

Firefox 152

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2032943

https://www.mozilla.org/security/advisories/mfsa2026-57/

Download the Critical Vulnerability Management Cheat Sheet

Timeline

Vulnerability published
Jun 16, 2026
Vulnerability Reserved
Jun 15, 2026

Credit

JunYoung Park

CVE-2026-12321 Data

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