High (8.1) in mozilla. EPSS 0.2% chance of exploitation in the next 30 days.
Site isolation issue in the Networking: Cookies component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Severity
CVSS 3.1
8.1 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS
0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-31)