Hmm. I don’t use gparted myself, so I do not know if an adapted script would work with gparted as well.
gparted carries an interim fix since 0.30: https://gparted.org/news.php?item=214 , but Ubuntu decided not to set ./configure --enable-xhost-root
[see Bug #1737248 “Do not use --enable-xhost-root” : Bugs : gparted package : Ubuntu and @jbicha’s reasoning for it]
Debian sets the workaround https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=883812 . So I guess that you could try to manually install the deb file from Debian Sid if you are adventurous: https://packages.debian.org/de/sid/amd64/gparted/download But don’t blame me if that kills your cat or breaks your Ubuntu 