Use After Free in Mozilla Firefox
CVE-2025-10527
Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 143, Firefox ESR 140.3, Thunderbird 143, and Thunderbird 140.3.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (18.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Mozilla Firefox — versions 140.3, 143
- Mozilla Thunderbird — versions 140.3, 143
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Broken Link)
- www.mozilla.org/security/advisories/mfsa2025-73/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-75/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-77/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-78/ (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-10527?
- CVE-2025-10527 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 7.1/10. Published 2025-09-16.
- How severe is CVE-2025-10527?
- High severity. CVSS v3 base score is 7.1 out of 10.
- Is CVE-2025-10527 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.