The "Forget about this site" feature in the History pane is intended to remove all saved user data that indicates a user has visited a site. This includes removing any HTTP Strict Transport Security (HSTS) settings received from sites that use it. Due to a bug, sites on the pre-load list also have their HSTS setting removed. On the next visit to that site if the user specifies an http: URL rather than secure https: they will not be protected by the pre-loaded HSTS setting. After that visit the site's HSTS setting will be restored. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.
{ "availability": "No subscription required", "binaries": [ { "binary_name": "firefox", "binary_version": "69.0+build2-0ubuntu0.16.04.4" }, { "binary_name": "firefox-dev", "binary_version": "69.0+build2-0ubuntu0.16.04.4" }, { "binary_name": "firefox-geckodriver", "binary_version": "69.0+build2-0ubuntu0.16.04.4" }, { "binary_name": "firefox-mozsymbols", "binary_version": "69.0+build2-0ubuntu0.16.04.4" } ] }
{ "availability": "No subscription required", "binaries": [ { "binary_name": "firefox", "binary_version": "69.0+build2-0ubuntu0.18.04.1" }, { "binary_name": "firefox-dev", "binary_version": "69.0+build2-0ubuntu0.18.04.1" }, { "binary_name": "firefox-geckodriver", "binary_version": "69.0+build2-0ubuntu0.18.04.1" }, { "binary_name": "firefox-mozsymbols", "binary_version": "69.0+build2-0ubuntu0.18.04.1" } ] }