Mozilla Firefox is vulnerable to denial of service attacks. It happens due to memory safety bugs fixed in Firefox.
access.redhat.com/errata/RHSA-2020:2033
access.redhat.com/security/updates/classification/#critical
bugzilla.mozilla.org/buglist.cgi?bug_id=1595886%2C1611482%2C1614704%2C1624098%2C1625749%2C1626382%2C1628076%2C1631508
security.gentoo.org/glsa/202005-03
security.gentoo.org/glsa/202005-04
usn.ubuntu.com/4373-1/
www.mozilla.org/security/advisories/mfsa2020-16/
www.mozilla.org/security/advisories/mfsa2020-17/
www.mozilla.org/security/advisories/mfsa2020-18/