Medium (6.5). EPSS 2.4% chance of exploitation in the next 30 days.
The Resource Timing API incorrectly revealed navigations in cross-origin iframes. This is a same-origin policy violation and could allow for data theft of URLs loaded by users. This vulnerability affects Firefox < 57, Firefox ESR < 52.5, and Thunderbird < 52.5.
Severity
CVSS 3.0
6.5 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS
2.4% chance of exploitation in the next 30 days; higher than 84% of CVEs (scores of 2026-10-31)