CVE-2022-26383: Mozilla Firefox

Medium severity, CVSS 4.3. EPSS: 0.7% chance of exploitation in the next 30 days.

When resizing a popup after requesting fullscreen access, the popup would not display the fullscreen notification. This vulnerability affects Firefox < 98, Firefox ESR < 91.7, and Thunderbird < 91.7.

Affected products

• Mozilla Firefox: before 98.0 (fixed in 98.0)
• Mozilla Firefox ESR: before 91.7 (fixed in 91.7)
• Mozilla Thunderbird: before 91.7 (fixed in 91.7)

Published 2022-12-22. Last modified 2026-06-17.