Mozilla · Firefox · CVE-2026-100808
**Name of the Vulnerable Software and Affected Versions**
Firefox ESR versions prior to 153.4
Firefox versions prior to 157
Thunderbird versions prior to 157
**Description**
A mitigation bypass exists within the DOM: Service Workers component. Service Workers are scripts that the browser runs in the background, separate from a web page, enabling features such as push notifications and offline access.
**Recommendations**
Update Firefox ESR to version 153.4.
Update Firefox to version 157.
Update Thunderbird to version 157.