High (7.5) in mozilla. EPSS 0.7% chance of exploitation in the next 30 days.
When resizing a popup while requesting fullscreen access, the popup would have become unable to leave fullscreen mode. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
0.7% chance of exploitation in the next 30 days; higher than 52% of CVEs (scores of 2026-10-31)