Improper privilege management in Firefox for Android and Mozilla Firefox - CVE-2026-16366
Published: July 22, 2026
Vulnerability identifier: #VU138996
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-16366
CWE-ID: CWE-269
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to escalate privileges.
The vulnerability exists due to improper access control in the DOM: Navigation component when handling navigation operations. A remote attacker can trigger crafted navigation behavior to escalate privileges.
Affected software
Firefox for Android
Mozilla Firefox
Mozilla Thunderbird
Mozilla Firefox
Mozilla Thunderbird
How to mitigate CVE-2026-16366
Install security update from vendor's website.
Firefox for Android - update to 153.0
Mozilla Firefox - update to 153.0
Mozilla Thunderbird - update to 153.0
Mozilla Firefox - update to 153.0
Mozilla Thunderbird - update to 153.0