Updated thunderbird packages fix security vulnerabilities:
Bypass of @namespace CSS sanitization during pasting (CVE-2019-17016)
Type Confusion in XPCVariant.cpp (CVE-2019-17017)
CSS sanitization does not escape HTML tags (CVE-2019-17022)
Memory safety bugs fixed in Thunderbird 68.4.1 (CVE-2019-17024)
IonMonkey type confusion with StoreElementHole and FallibleStoreElement (CVE-2019-17026)
Enigmail has been updated to 2.15