Mozilla developer Peter Van der Beken discovered that same-origin XrayWrappers expose chrome-only properties even when not in a chrome compartment. This can allow web content to get properties of DOM objects that are intended to be chrome-only.
In general these flaws cannot be exploited through email in the Thunderbird and SeaMonkey products because scripting is disabled, but are potentially a risk in browser or browser-like contexts in those products.
Vulmon