CVE Catalog
CVE-2026-74986
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk0.15%
5th percentile - higher than 5% of all known CVEs
Summary
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.
Risk Assessment
An attacker could exploit the site isolation issue to breach security boundaries between sites, potentially leading to data disclosure or unauthorized actions.
Recommendation
Update Firefox and Thunderbird to the versions mentioned in the description to receive security fixes.
Original NVD description (English source)
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.