CVE-2026-5600

A new API endpoint introduced in pretix 2025 that is supposed to 
return all check-in events of a specific event in fact returns all 
check-in events belonging to the respective organizer. This allows an 
API consumer to access information for all other events under the same 
organizer, even those they should not have access to.


These records contain information on the time and result of every ticket scan as well as the ID of the matched ticket. Example:


{
  "id": 123,
  "successful": true,
  "error_reason": null,
  "error_explanation": null,
  "position": 321,
  "datetime": "2020-08-23T09:00:00+02:00",
  "list": 456,
  "created": "2020-08-23T09:00:00+02:00",
  "auto_checked_in": false,
  "gate": null,
  "device": 1,
  "device_id": 1,
  "type": "entry"
}



An unauthorized user usually has no way to match these IDs (position) back to individual people.