More information about this security flaw is available in the following bug: https://bugzilla.redhat.com/show_bug.cgi?id=2364868 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.
There is jruby-complete.jar included in the release tarball, which might be vulnerable. But I don't think it is used for purpose of this package. Therefore selenium-manager is not vulnerable and this is NOTABUG. But given the .jar file size, it would IMHO make sense to omit it from the source tarball.