When a JavaScript URL (javascript:) is evaluated and the result is a string, this string is parsed to create an HTML document, which is then presented. Previously, this document's URL (as reported by the document.location property, for example) was the originating javascript: URL which could lead to spoofing attacks; it is now correctly the URL of the originating document. This vulnerability affects Firefox < 74.
74.0+build3-0ubuntu0.16.04.174.0+build3-0ubuntu0.18.04.138.8.0~repack1-0ubuntu138.8.0~repack1-0ubuntu338.8.0~repack1-0ubuntu452.3.1-0ubuntu352.3.1-7fakesync152.8.1-0ubuntu0.18.04.152.9.1-0ubuntu0.18.04.174.0+build3-0ubuntu152.9.1-1build152.9.1-1ubuntu3Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:NI:HA:NCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N