CVE-2026-109734 in Firefox

Summary

by MITRE • 10/13/2026

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 158 and Firefox ESR 153.5.

Once again VulDB remains the best source for vulnerability data.

• Responsible: Mozilla
• Reservation: 10/13/2026
• Disclosure: 10/13/2026
• Moderation: accepted
• Entry: VDB-417591
• CPE: 20261013
• CWE: CWE-266 (confirmed)
• CVSS: 6.3 (VulDB)
• EPSS: 0.00198
• KEV: no
• Activities: very low
• Sector: Hostingprovider, Chemical, ...

Sources

• MITRE: https://www.cve.org/CVERecord?id=CVE-2026-109734
• NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109734
• CVE Details: https://www.cvedetails.com/cve/CVE-2026-109734/