teler is an real-time intrusion detection and threat alert dashboard. teler prior to version 2.0.0-rc.4 is vulnerable to DOM-based cross-site scripting (XSS) in the teler dashboard. When teler requests messages from the event stream on the `/events` endpoint, the log data displayed on the dashboard are not sanitized. This only affects authenticated users and can only be exploited based on detected threats if the log contains a DOM scripting payload. This vulnerability has been fixed on version `v2.0.0-rc.4`. Users are advised to upgrade. There are no known workarounds for this vulnerability.