corrective release of Firefox 78.0.2, which fixes and fixed several bugs. Vulnerability allows you to bypass restrictions set through the header , and substitute content from another site using object or embed tags.
Of the corrections, the solution is noted with facilities for people with disabilities and the elimination of regressive , preventing opening links in external applications (in Firefox 78, the value of the security.allow_disjointed_external_uri_loads setting was changed). In addition, the resistance of the address bar to data corruption in the user profile has been increased (search stopped working if the profile was damaged).
Source: opennet.ru