More information about this security flaw is available in the following bug: https://bugzilla.redhat.com/show_bug.cgi?id=2311152 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.
express is not used by yarn (it is only referenced in a testdata yarn.lock).