CVE-2023-25730: Mozilla Firefox

Medium severity, CVSS 5.4. EPSS: 0.5% chance of exploitation in the next 30 days.

A background script invoking <code>requestFullscreen</code> and then blocking the main thread could force the browser into fullscreen mode indefinitely, resulting in potential user confusion or spoofing attacks. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

Affected products

• Mozilla Firefox: before 110.0 (fixed in 110.0)
• Mozilla Firefox ESR: before 102.8 (fixed in 102.8)
• Mozilla Thunderbird: before 102.8 (fixed in 102.8)

Published 2023-06-02. Last modified 2026-06-17.