Buffer overflow in Mozilla Firefox
CVE-2025-14333
Memory safety bugs present in Firefox ESR 140.5, Thunderbird ESR 140.5, Firefox 145 and Thunderbird 145. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 146, Firefox ESR 140.6, Thunderbird 146, and Thunderbird 140.6.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (35.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
- Mozilla Firefox — versions 140.6, 146
- Mozilla Thunderbird — versions 140.6, 146
Weakness classification (CWE)
References
- bugzilla.mozilla.org/buglist.cgi (Issue Tracking, Broken Link)
- www.mozilla.org/security/advisories/mfsa2025-92/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-94/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-95/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-96/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-14333?
- CVE-2025-14333 is a high-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 8.1/10. Published 2025-12-09.
- How severe is CVE-2025-14333?
- High severity. CVSS v3 base score is 8.1 out of 10.