More information about this security flaw is available in the following bug: https://bugzilla.redhat.com/show_bug.cgi?id=2366703 Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
python-flit does not use tornado at all, and even if it did, tornado CVEs would need to be fixed in that package, not here.