Vulnerability Details CVE-2026-74986
Site isolation issue in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 28.1%
CVSS Severity
CVSS v3 Score 9.1