Low (3.7) in mozilla. EPSS 1.8% chance of exploitation in the next 30 days.
Navigation events were not fully adhering to the W3C's "Navigation-Timing Level 2" draft specification in some instances for the unload event, which restricts access to detailed timing attributes to only be same-origin. This resulted in potential cross-origin information exposure of history through timing side-channel attacks. This vulnerability affects Firefox < 69, Thunderbird < 68.1, Thunderbird < 60.9, Firefox ESR < 60.9, and Firefox ESR < 68.1.
Severity
CVSS 3.1
3.7 low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS
1.8% chance of exploitation in the next 30 days; higher than 78% of CVEs (scores of 2026-10-31)