Use After Free in Mozilla Firefox
CVE-2026-0885
Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Vulnerability class: Use-After-Free
EPSS: 0.004 (27.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.
Affected products
- Mozilla Firefox — versions 140.7, 147
- Mozilla Thunderbird — versions 140.7, 147
Weakness classification (CWE)
References
- security@mozilla.org (Permissions Required)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-0885?
- CVE-2026-0885 is a medium-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 6.5/10. Published 2026-01-13.
- How severe is CVE-2026-0885?
- Medium severity. CVSS v3 base score is 6.5 out of 10.