Mozilla · Firefox · CVE-2026-84136
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 155
Firefox ESR versions prior to 153.2
Thunderbird versions prior to 155
Thunderbird versions prior to 153.2
**Description**
An issue exists within the Document Object Model (DOM) specifically affecting the Navigation component.
**Recommendations**
Update Firefox to version 155.
Update Firefox ESR to version 153.2.
Update Thunderbird to version 155.
Update Thunderbird to version 153.2.