Out-of-bounds Read in Mozilla Firefox
CVE-2026-12298
Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
Vulnerability class: Buffer Overflow
EPSS: 0.003 (22.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
Affected products
- Mozilla Firefox — versions 140.12, 152
- Mozilla Thunderbird — versions 140.12, 152
Weakness classification (CWE)
References
- security@mozilla.org (Permissions Required)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-12298?
- CVE-2026-12298 is a medium-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Read. CVSS score: 5.4/10. Published 2026-06-16.
- How severe is CVE-2026-12298?
- Medium severity. CVSS v3 base score is 5.4 out of 10.