CVE-2026-16388 is a sandbox escape vulnerability affecting the DOM Networking component in Mozilla Firefox. It allows an attacker to escape the browser's sandbox, which is a security mechanism designed to isolate processes and limit the impact of exploits. The vulnerability was fixed in Firefox 153. According to the Mozilla security advisory MFSA 2026-68, this issue has a moderate impact rating. No further technical details or exploitation methods are provided in the advisory. There are no known exploits in the wild at the time of publication.

The vulnerability enables sandbox escape in the DOM Networking component, which could allow an attacker to bypass security restrictions imposed by the sandbox. This may lead to unauthorized access or privilege escalation within the browser environment. The impact is rated as moderate by the vendor. No active exploitation has been reported.

A fix for this vulnerability is available in Firefox version 153. Users and administrators should update to Firefox 153 or later to remediate this issue. There is no indication that additional mitigation steps are required beyond applying the official update.