CVE-2026-109778

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.

Detection

No reliable host or network indicator is derivable from the published description.

Prioritized remediation

Upgrade to Firefox 158 or Thunderbird 158, as these versions contain the fix for CVE-2026-109778.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.