Mozilla · Firefox · CVE-2026-16390
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 153
Firefox ESR versions prior to 140.13
Thunderbird versions prior to 153
Thunderbird versions prior to 140.13
**Description**
A mitigation bypass exists within the Enterprise Policies component.
**Recommendations**
Update Firefox to version 153 or later.
Update Firefox ESR to version 140.13 or later.
Update Thunderbird to version 153 or later.
Update Thunderbird to version 140.13 or later.