{"id":"CVE-2026-109778","published":"2026-10-13T13:17:28.713","lastModified":"2026-10-14T04:18:17.137","description":"Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.","cvssScore":8.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cwes":["CWE-269"],"vendors":[],"products":[],"references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2070547","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-109/","tags":[]},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-110/","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"A privilege escalation vulnerability in Firefox and Thunderbird's WebExtensions component allows attackers to gain elevated privileges, potentially leading to full system compromise. This affects users running vulnerable versions of these applications.","exploitability":"Exploitation requires user interaction via a malicious website or extension, making it moderately difficult to achieve without social engineering, but once triggered, the vulnerability can be reliably exploited.","blast_radius":"If exploited, this vulnerability could allow attackers to execute arbitrary code with elevated privileges on the victim's system, potentially leading to complete system compromise or data exfiltration.","remediation":"Upgrade to Firefox 158 or Thunderbird 158, as these versions contain the fix for CVE-2026-109778.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["privilege-escalation","webextensions","browser"],"model":"garnet-coder","analyzedAt":"2026-10-16T09:04:23.168Z"}}