Yes, the bug was filled at the Proxmox Bugtracker here: https://bugzilla.proxmox.com/show_bug.cgi?id=2243
It is already patched since
pve-kernel-5.0.21-2-pve
Unfortunately, as it took some time until it was patched and I had to find a workaround, I was not able to test the patch yet.
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