CVE-2026-8389highCWE-119 CWE-686 CWE-733 CWE-843

CVE-2026-8389: high-severity vulnerability in Mozilla Firefox

JIT miscompilation in the JavaScript Engine: JIT component

Published 12 May 2026 · Updated 15 Jul 2026

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43Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 8.8epss 0.4%

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3.

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

Affected products

Mozilla · Firefox

public PoCs found — 1

cve_referencegithub.com/crixpwn/CVE-2026-8389★ 40

⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.

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References

https://access.redhat.com/security/cve/CVE-2026-8389 https://bugzilla.mozilla.org/show_bug.cgi?id=2036983 https://bugzilla.redhat.com/show_bug.cgi?id=2476466 https://github.com/crixpwn/CVE-2026-8389 https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8389.json https://www.mozilla.org/security/advisories/mfsa2026-45/