Does your JIRA also show all Filters which are "shared with all users" to really everyone in the world?
Just try the following:
As you can see - without logging in you can get information about saved filters and names + mail adress from the filter owner.
Does your JIRA also show all Dashboards which are "shared with all users" to really everyone in the world?
Just try the following:
As you can see - without logging in you can get information about saved Dashboards and names from the dashboard owner.
Also you are not logged in JIRA is interacting with so called anonymous user. Here you find some examples:
Also you won't get any issue data, the JIRA system is responding and interacting.
If you think this is not an acceptable behaviour.