thunderbird is vulnerable to Denial Of Service (DoS). An attacker can cause an application crash through the memory corruption in the library
git://git.launchpad.net/ubuntu-cve-tracker/tree/active/CVE-2021-4129
bugzilla.mozilla.org/buglist.cgi?bug_id=1393362%2C1736046%2C1736751%2C1737009%2C1739372%2C1739421
www.mozilla.org/security/advisories/mfsa2021-52/
www.mozilla.org/security/advisories/mfsa2021-53/
www.mozilla.org/security/advisories/mfsa2021-54/