CVE-2026-109739
Privilege escalation in the WebExtensions component.
Published Oct 13, 2026 · updated Oct 14, 2026
Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
Timeline
Detection, updates, and resolution for this record.
Oct 13, 2026 · NIST NVD
Detected
Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
Oct 14, 2026 · NIST NVD
Updated
Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
Sources
- CVE.orgCVE-2026-109739
Official CVE identifier
cve.org - FIRST EPSSCVE-2026-109739
30-day exploitation probability 0.2%
first.org - NIST NVDCVE-2026-109739
Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
nvd.nist.gov