Out-of-bounds Read in Mozilla Firefox
CVE-2026-6785
Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could…
Vulnerability class: Buffer Overflow
EPSS: 0.000 (4.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Mozilla Firefox — versions 115.35, 140.10, 150
- Mozilla Thunderbird — versions 140.10, 150
Weakness classification (CWE)
References
- security@mozilla.org (Broken Link)
- security@mozilla.org (Vendor Advisory)
- 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-2026-6785?
- CVE-2026-6785 is a high-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-04-26.
- How severe is CVE-2026-6785?
- High severity. CVSS v3 base score is 7.5 out of 10.