CVE-2023-5725: Debian Linux

Medium severity, CVSS 4.3. EPSS: 0.9% chance of exploitation in the next 30 days.

A malicious installed WebExtension could open arbitrary URLs, which under the right circumstance could be leveraged to collect sensitive user data. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only
• Mozilla Firefox: before 119.0 (fixed in 119.0)
• Mozilla Firefox ESR: before 115.4 (fixed in 115.4)
• Mozilla Thunderbird: before 115.4.1 (fixed in 115.4.1)

Published 2023-10-25. Last modified 2026-06-17.