[86] Rendering to string is unsafe

Following the approach described in https://medium.com/node-security/the-most-common-xss-vulnerability-in-react-js-applications-2bdffbcc1fa0#.mup3jwgjq I have tried the following use data string in a page

<template>
  <div>
    <h1>Welcome</h1>
  </div>
</template>

<script>
export default {
  data () {
    return {
      whatever: '</script><script>console.log("xss")</script>'
    }
  }
}
</script>

which prints "xss" during server-side rendering on the server and in the browser console for client rendering. I believe this is due to unsafe object serialization in self.renderToString