The bug allows malicious players to execute commands through your computers shell. This means that they can directly affect your PC, and cause potential harm. The issue is present in Minecraft Java versions as early as 1.7 up to 1.18.
Keep in mind it is completely up to YOU whether or not you want to or feel comfortable to make this change.
How to fix the issue on your client:
1. Open your Minecraft Launcher and go to "Installations"
2. Click the three dots, and click edit
3. Click "More options"
4. Located your "JVM Arguments", DO NOT remove anything from the box
5. Go to the end of your "JVM Arguments", add a space and copy and paste the following line:
-Dlog4j2.formatMsgNoLookups=true
6. Save your changes and launch your client
