Medium (6.5) in mozilla. EPSS 0.7% chance of exploitation in the next 30 days.
Securitypolicyviolation events could have leaked cross-origin information for frame-ancestors violations. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS
0.7% chance of exploitation in the next 30 days; higher than 52% of CVEs (scores of 2026-11-01)