{"id":"CVE-2026-74960","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74960","summary":"Site isolation issue in the WebExtensions 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.","details":"Site isolation issue in the WebExtensions 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.","published":"2026-08-18T13:17:33.170","modified":"2026-08-18T19:17:11.543","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2049148"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-74/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-76/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-77/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-78/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-79/"},{"type":"WEB","url":"https://www.mozilla.org/security/advisories/mfsa2026-80/"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T19:17:11.543"}}