CVE-2026-12321

JIT miscompilation in the JavaScript: WebAssembly component

Published Jun 16, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
Vendors & Products Mozilla thunderbird
Type Values Removed Values Added
Description JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 152. JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 152 and Thunderbird 152.
References
Type Values Removed Values Added
Weaknesses CWE-670
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox
Type Values Removed Values Added
Description JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 152.
Title JIT miscompilation in the JavaScript: WebAssembly component
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mozilla
Published
Updated
Jun 16, 2026, 4:08 PM
Reserved
Jun 15, 2026, 3:08 PM
Status
Analyzed
Published
Jun 16, 2026, 1:16 PM
Modified
Oct 26, 2026, 12:10 PM
Severity
Low
Public date
Jun 16, 2026, 11:52 AM