CVE-2026-12321

JIT miscompilation in the JavaScript: WebAssembly component

CVSS 5.4 MEDIUMEPSS 0.2%CWE-670

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 5.4EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

16 Jun 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Affected products

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References