RCE in Mozilla Firefox

CVE-2025-4089

Due to insufficient escaping of special characters 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 vulnerability was fixed in Firefox 138 and Thunderbird 138.

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.002 (6.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-4089?
CVE-2025-4089 is a medium-severity vulnerability in Mozilla Firefox, classified under Command Injection. CVSS score: 5.1/10. Published 2025-04-29.
How severe is CVE-2025-4089?
Medium severity. CVSS v3 base score is 5.1 out of 10.