A same-origin policy violation allowing the theft of cross-origin URL entries when using a meta http-equiv="refresh" on a page to cause a redirection to another site using performance.getEntries(). This is a same-origin policy violation and could allow for data theft. This vulnerability affects Firefox < 62, Firefox ESR < 60.2, and Thunderbird < 60.2.1.
https://www.mozilla.org/security/advisories/mfsa2018-25/
https://www.mozilla.org/security/advisories/mfsa2018-21/