firefox is vulnerable to information disclosure. The vulnerability exists as internal network hosts, and services running on the user’s local machine, could have been probed by a malicious webpage.
bugzilla.mozilla.org/show_bug.cgi?id=1677047
git.launchpad.net/ubuntu-cve-tracker/tree/active/CVE-2020-26978
www.mozilla.org/en-US/security/advisories/mfsa2020-54/
www.mozilla.org/security/advisories/mfsa2020-54/
www.mozilla.org/security/advisories/mfsa2020-55/
www.mozilla.org/security/advisories/mfsa2020-56/