Vulnerability in Mozilla Firefox
CVE-2025-9181
Uninitialized memory in the JavaScript Engine component. This vulnerability was fixed in Firefox 142, Firefox ESR 128.14, Firefox ESR 140.2, Thunderbird 142, Thunderbird 128.14, and Thunderbird 140.2.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (27.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.3% 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 128.14, 140.2, 142
- Mozilla Thunderbird — versions 128.14, 140.2, 142
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2025-64/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-66/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-67/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-70/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-71/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-72/ (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-9181?
- CVE-2025-9181 is a medium-severity vulnerability in Mozilla Firefox, classified under CWE-457. CVSS score: 6.5/10. Published 2025-08-19.
- How severe is CVE-2025-9181?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2025-9181 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.