A thunderbird Security Update has been released for CentOS 7

CentOS Errata and Security Advisory 2019:4148 Important

Upstream details at :   https://access.redhat.com/errata/RHSA-2019:4148

The following updated files have been uploaded and are currently
syncing to the mirrors: ( sha256sum Filename )

x86_64:
dcc2fa6aa9fb5603a0d4487c09204a21f4cf1359459c3533af426aff3e26fe25 thunderbird-68.3.0-1.el7.centos.x86_64.rpm

Source:
cdecc802093528ac881d742cc0c264f82e0133fe50a3612a3f357e05430135cf thunderbird-68.3.0-1.el7.centos.src.rpm