CVE-2025-4089: Mozilla Firefox

Medium severity, CVSS 5.1. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Mozilla Firefox: before 138.0 (fixed in 138.0)
• Mozilla Thunderbird: before 138.0 (fixed in 138.0)

Published 2025-04-29. Last modified 2026-09-30.