{"id":"CVE-2026-74989","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74989","summary":"Internally found bugs present in Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort…","details":"Internally found bugs present in Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154 and Thunderbird 154.","published":"2026-08-18T13:17:40.810","modified":"2026-08-20T19:49:36.153","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/buglist.cgi?bug_id=2022257%2C2027351%2C2027380%2C2029289"},{"type":"WEB","url":"https://bugzilla.mozilla.org/buglist.cgi?bug_id=2027388%2C2029750%2C2029794%2C2043298%2C2045126%2C2049810%2C2051741"},{"type":"ADVISORY","url":"https://www.mozilla.org/security/advisories/mfsa2026-74/"},{"type":"ADVISORY","url":"https://www.mozilla.org/security/advisories/mfsa2026-78/"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-08-20T19:49:36.153"}}