RCE in Mozilla Firefox
CVE-2025-5265
Due to insufficient escaping of the ampersand character in the “Copy as cURL” feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.*. This vulnerability was fixed in Firefox 139, Firefox ESR 115.24, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
Vulnerability class: Command Injection (OS Command Injection)
EPSS: 0.002 (6.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L.
Affected products
- Mozilla Firefox — versions 115.24, 128.11, 139
- Mozilla Thunderbird — versions 128.11, 139
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
- security@mozilla.org
Frequently asked questions
- What is CVE-2025-5265?
- CVE-2025-5265 is a medium-severity vulnerability in Mozilla Firefox, classified under Command Injection. CVSS score: 4.8/10. Published 2025-05-27.
- How severe is CVE-2025-5265?
- Medium severity. CVSS v3 base score is 4.8 out of 10.