{"id":"CVE-2026-109780","title":"Mitigation bypass in the DOM: Core & HTML component","summary":"Mitigation bypass in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.","severity":"critical","published":"2026-10-13","updated":"2026-10-13","sourceUpdated":"2026-10-13T19:18:42.560","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-109780","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2072775","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-109/","label":"security@mozilla.org"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-13T13:27:04.018Z","vendor":"Mozilla","product":"Firefox","affected":["Firefox","Thunderbird"],"epss":0.00363,"epssPercentile":0.29951,"cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-26T19:21:41.229525Z"},"cvssSource":"adp","slug":"CVE-2026-109780","body":"## Overview\n\nMitigation bypass in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":229772,"id":"CVE-2026-109780","ts":1793047363978,"field":"cvss","old":null,"new":"9.8"},{"seq":229771,"id":"CVE-2026-109780","ts":1793047363978,"field":"severity","old":"none","new":"critical"}]}