CVE-2020-6824
Initially, a user opens a Private Browsing Window and generates a password for a site, then closes the Private Browsing Window but leaves Firefox open. Subsequently, if the user had opened a new Private Browsing Window, revisited the same site, and generated a new password – the generated passwords would have been identical, rather than independent. This vulnerability affects Firefox < 75.
Source: CVE-2020-6824