Buffer overflow in Mozilla Firefox
CVE-2025-1017
Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
Vulnerability class: Buffer Overflow
EPSS: 0.006 (43.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Mozilla Firefox — versions 128.7, 135
- Mozilla Thunderbird — versions 128.7, 135
Weakness classification (CWE)
Public proof-of-concept exploits
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)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-1017?
- CVE-2025-1017 is a critical-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2025-02-04.
- How severe is CVE-2025-1017?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2025-1017 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.