Medium (5.3) in mozilla. EPSS 0.3% chance of exploitation in the next 30 days.
The origin of an external protocol handler prompt could have been obscured using a data: URL within an `iframe`. This vulnerability affects Firefox < 132, Firefox ESR < 128.4, Thunderbird < 128.4, and Thunderbird < 132.
Severity
CVSS 3.1
5.3 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS
0.3% chance of exploitation in the next 30 days; higher than 27% of CVEs (scores of 2026-10-31)