Medium (6.5) in mozilla. EPSS 1.1% chance of exploitation in the next 30 days.
Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
EPSS
1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)