Buffer overflow in Mozilla Firefox
CVE-2025-9179
An attacker was able to perform memory corruption in the GMP process which processes encrypted media. This process is also heavily sandboxed, but represents slightly different privileges from the content process. This vulnerability was fixed in Firefox 142, Firefox ESR 115.27, Firefox ESR 128.14, Firefox ESR 140.2, Thunderbird 142, Thunderbird 128.14, and Thunderbird 140.2.
Vulnerability class: Buffer Overflow
EPSS: 0.006 (43.5th 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 115.27, 128.14, 140.2
- Mozilla Thunderbird — versions 128.14, 140.2, 142
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security@mozilla.org (Permissions Required, Issue Tracking)
- 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)
- security@mozilla.org (Vendor Advisory)
- security@mozilla.org (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2025-9179?
- CVE-2025-9179 is a critical-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2025-08-19.
- How severe is CVE-2025-9179?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2025-9179 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.