https://cyberplace.social/@GossiTheDog/112194735806991939
"4 days since XZ backdoor became public knowledge and most major Linux AV and EDR security vendors still have zero detections.. they haven’t even set the static file hashes as malicious.
Can’t wait for all the vendor blogs in a week saying they fully protect against the threat. 👍"
The answer to your question: no.
Not sure whether it can fix the font problem, but in general Flatseal allows you to customise permissions for installed flatpaks.
https://flathub.org/apps/com.github.tchx84.Flatseal