Security researcher Mariusz Mlynski discovered an issue where sites that have been given notification permissions by a user can bypass security checks on source components for the Web Notification API. This allows for script to be run in a privileged context through notifications, leading to arbitrary code execution on these sites.
In general this flaw cannot be exploited through email in the Thunderbird and Seamonkey products because scripting is disabled, but is potentially a risk in browser or browser-like contexts.
Vulmon