NOTICE: Grav found potential XSS issues in content: 'dangerous_tags'

I hope this is not a duplicate. Sorry if it’s the case.

After updating the admin panel (to the current version), I’m getting a notification in a green box above every page:

NOTICE: Grav found potential XSS issues in content: 'dangerous_tags’

I have no clue what those mean. Can you help out? Thanks.