A new bug-fix update for the 1.12.x branch came out, specifically targeted for RHEL 9: https://github.com/flatpak/flatpak/releases/tag/1.12.8 Most interestingly, it includes some security fixes (bug 2180312) and addresses several SELinux denials encountered in Fedora (bug 2053634, bug 2070350, bug 2070741, bug 2071215, bug 2071217). We are currently carrying flatpak-1.12.7 in RHEL 9. flatpak-1.12.8 was already built for Fedora 36 in March 2023 before it went EOL, so it has had some testing.
Merge request: https://gitlab.com/redhat/centos-stream/rpms/flatpak/-/merge_requests/16
Built flatpak-1.12.8-1.el9: https://kojihub.stream.rdu2.redhat.com/koji/taskinfo?taskID=2465422