CVE-2026-16371 is a privilege escalation vulnerability affecting the DOM: Navigation component in Mozilla Firefox. This vulnerability allows an attacker to gain elevated privileges within the browser context, potentially compromising security boundaries. The issue was addressed and fixed in Firefox 153 and Firefox ESR 140.13. The CVSS v3.1 base score is 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, and high impact on confidentiality, integrity, and availability. The Mozilla Foundation security advisories MFSA 2026-68 and MFSA 2026-70 provide detailed information and confirm the remediation status.

Successful exploitation of this vulnerability could allow an attacker to escalate privileges within the Firefox browser, potentially leading to unauthorized access to sensitive information, modification of data, or disruption of service. The high CVSS score reflects the critical nature of the impact on confidentiality, integrity, and availability. However, there are no known active exploits in the wild at this time.

A fix for this vulnerability is available and has been incorporated into Firefox version 153 and Firefox ESR version 140.13. Users and administrators should update affected Firefox installations to these versions or later to mitigate the risk. The vendor advisory does not indicate any additional mitigation steps or workarounds, so applying the official update is the recommended action.