More information about this security flaw is available in the following bug: https://bugzilla.redhat.com/show_bug.cgi?id=2373147 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.
glycin does not include gdk-pixbuf, it only dynamically links it. As such, this issue needs to be fixed in the gdk-pixbuf2 package.