Dashboard shows cluster of different user

**What happened**:

We are running a jupyterhub for HPC users. I noticed when opening jupyterlab that the Dask Dashboard is activated and shows a running cluster on port `8787`even if I didn't start a cluster before. After checking who is using that port it is actually a different user.
How can that be possible? the should not be possible right (security perspective)?
**What you expected to happen**:

**Anything else we need to know?**:

**Environment**:

- Dask version: 2022.02.0
- Dask-Labextension version: 5.2.0
- Python version: 3.9
- Operating System: CentOS 8
- Install method (conda, pip, source): conda

Cluster Dump State: