Use After Free in Mozilla Firefox

CVE-2026-8390

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150.0.3.

Vulnerability class: Use-After-Free

EPSS: 0.000 (4.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

Affected products

Mozilla Firefox — versions 150.0.3

Weakness classification (CWE)

CWE-416 — Use After Free

References

security@mozilla.org (Permissions Required)
security@mozilla.org (Vendor Advisory)

Frequently asked questions

What is CVE-2026-8390?: CVE-2026-8390 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 7.3/10. Published 2026-05-12.
How severe is CVE-2026-8390?: High severity. CVSS v3 base score is 7.3 out of 10.