A vulnerability in the notifications Push API where notifications can be sent through service workers by web content without direct user interaction. This could be used to open new tabs in a denial of service (DOS) attack or to display unwanted content from arbitrary URLs to users. This vulnerability affects Firefox < 59.
https://www.mozilla.org/security/advisories/mfsa2018-06/
https://usn.ubuntu.com/3596-1/
https://bugzilla.mozilla.org/show_bug.cgi?id=1429093