Has been available for a week; doesn't seem to have been picked up automatically: http://ftp.gnome.org/pub/GNOME/sources/glade/3.20/
glade-3.20.3-1.fc27 has been submitted as an update to Fedora 27. https://bodhi.fedoraproject.org/updates/FEDORA-2018-7aa4244196
glade-3.20.3-1.fc27 has been pushed to the Fedora 27 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-7aa4244196
glade-3.20.3-1.fc27 has been pushed to the Fedora 27 stable repository. If problems still persist, please make note of it in this bug report.