Buffer overflow in Mozilla Firefox
CVE-2026-92035
Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Thunderbird 140.17, Firefox 156, Firefox ESR 153.3, Thunderbird 156, Thunderbird 153.3, Firefox ESR 115.42, and Firefox ESR 140.17.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (25.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 25.9% 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
Weakness classification (CWE)
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required)
- www.mozilla.org/security/advisories/mfsa2026-90/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-93/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-94/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-96/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-98/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-99/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2026-102/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-92035?
- CVE-2026-92035 is a critical-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.6/10. Published 2026-09-15.
- How severe is CVE-2026-92035?
- Critical severity. CVSS v3 base score is 9.6 out of 10.