Indeed, all commonly-used hypervisors have had host escape vulnerabilities reported over the years, including Xen as used in Qubes - see e.g. http://blog.quarkslab.com/xen-exploitation-part-3-xsa-182-qu...

Of relevance to Edge exploitation, Microsoft are currently working on a Qubes-like sandboxing model for Edge, based on Hyper-V (though it looks like it'll be aimed towards enterprise customers rather than consumer): https://blogs.windows.com/msedgedev/2016/09/27/application-g.... Will be interesting to see if that's part of the challenge in Pwn2Own 2018. Somewhat surprisingly, Hyper-V wasn't successfully exploited at this year's contest.