Panic! Panic! All of my private repositories disappeared

All of my private repositories have disappeared

Repositories of all of my projects suddenly disappeared. It was still there, but when I open my project it says:

“No repository
The repository for this project does not exist.
This means you can not push code until you create an empty repository or import existing one.”

I’m using the Gitlab CE installed on Ubuntu 20.04 LTS locally.

I did check the local repositories directory and it is not empty:

Has 511 MB of data

I hope someone could help me with this. Thanks in advance.

Please refer to CVE-2021-22205: How to determine if a self-managed instance has been impacted - #24 by gitlab-greg.