Medium (6.5) in mozilla. EPSS 0.6% chance of exploitation in the next 30 days.
An attacker could have injected CSS into stylesheets accessible via internal URIs, such as resource:, and in doing so bypass a page's Content Security Policy. This vulnerability affects Firefox ESR < 91.11, Thunderbird < 102, Thunderbird < 91.11, and Firefox < 101.
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
0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-31)