{"id":"CVE-2026-109778","title":"Privilege escalation in the WebExtensions component","summary":"Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5.","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cwe":["CWE-269"],"published":"2026-10-13","updated":"2026-10-13","sourceUpdated":"2026-10-13T16:19:16.897","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-109778","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2070547","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","label":"security@mozilla.org"}],"tags":["nvd"],"ingestedAt":"2026-10-13T13:27:04.017Z","slug":"CVE-2026-109778","body":"## Overview\n\nPrivilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":219791,"id":"CVE-2026-109778","ts":1791905700123,"field":"cvss","old":null,"new":"8.8"},{"seq":219790,"id":"CVE-2026-109778","ts":1791905700123,"field":"severity","old":"none","new":"high"}]}