ZoomEye finds 5.6 million exposed MQTT services online

ZoomEye's index as of October 23, 2026 shows 5,623,921 matches for the MQTT service, with 4,740,183 on port 1883. The remaining 883,738 run on other ports and are missed by port-scoped queries. Many brokers allow anonymous connections and subscription to #.

• ZoomEye: 5,623,921 matches for service="mqtt"
• 4,740,183 on port 1883, 883,738 on other ports
• Anonymous subscribe to # exposes the full telemetry stream
• Anonymous publish lets clients write values acted on downstream