{"id":"CVE-2026-84140","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-84140","summary":"Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.","details":"Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.","published":"2026-09-01T12:19:07.017Z","modified":"2026-09-03T17:23:51.826Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2063780"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-82/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-85/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-86/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-88/"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-09-03T17:23:51.826Z"}}