senn-techA coffee machine sent 1 TB in 10 days: put IoT on its own VLAN
On 6 October 2026 the user Nomad posted statistics for a Keurig K-Supreme SMART on X. The connected pod machine caused 1,008.45 GB of upload and 9.94 GB of download in a little over ten days. He found it while doing remote maintenance on his parents' home network, in the UniFi network management. SmarthomeAssistent and IT-Connect picked up the case. What the machine did with the data is open. As a case for network planning it still works.
The numbers
IT-Connect gives the duration as 10 days and 9 hours and works it out to about 97 GB per day, around 9 Mbit/s on average. The arithmetic holds: 1,008.45 GB over just over 10.4 days is about 97 GB per day.
According to the manufacturer, the machine uses only the 2.4 GHz band with WPA2-PSK. A client transmitting continuously on that band takes airtime from the other devices. That is our reading; the reports do not say so. The user reports that the access point was loaded so heavily that connectivity suffered at times. A complete network outage apparently did not happen.
Where did the traffic go?
At first it was unclear where the data went. An investigation showed, according to SmarthomeAssistent, that most of it stayed on the local network and never reached the internet. Nomad suspects a bug in the machine's network stack. He cannot prove it, and there is no packet capture. IT-Connect regrets that no Wireshark capture exists.
Two statements seem to conflict at first. SmarthomeAssistent writes that after the restart and the move into the VLAN the problem did not return. IT-Connect, citing Nomad, writes that the behavior is said to come back once the device regains internet access. Both can be true if the device stays quiet in an isolated VLAN, perhaps because it has no internet there. That is our guess; the reports only mention a separate VLAN. The reports allow no more than that reading.
What follows for networks
This is a single case and proves no vulnerability. It does show how an unattended device can load a wireless network without anyone noticing, until someone happens to look at the statistics. Three measures follow, and they hold regardless of this particular machine:
- Put IoT devices on their own VLAN, with internet access only where the device needs it.
- Look at per-client data regularly, or set a threshold, in the network management or via NetFlow. A device that sends more than it receives stands out by its ratio before the volume gets large.
- Where possible, put 2.4 GHz devices on an access point of their own, so they do not eat the airtime of the others.
Further reading
- 1 TB in zehn Tagen: Smarte Kaffeemaschine verursacht Datenflut (SmarthomeAssistent, 8 October 2026, German): numbers, suspected cause, VLAN
- Keurig Smart Coffee Machine Sends Over 1 TB of Data in 10 Days on Wi-Fi (IT-Connect, 12 October 2026): second source, 2.4 GHz note
- Simple Icons: ubiquiti.svg: logo, CC0
How much data did the Keurig coffee machine send?+
According to the UniFi statistics the user Nomad showed on X, 1,008.45 GB of upload and 9.94 GB of download in a little over ten days. IT-Connect works that out to about 97 GB per day, or roughly 9 Mbit/s sustained. Most of the traffic stayed on the local network, according to the user.
Is the cause known?+
No. The user suspects a bug in the machine's network stack. That is unconfirmed, and Keurig has not commented so far. It is a single publicly documented case. A fundamental security problem or an unauthorized transfer of personal data cannot be derived from it, says SmarthomeAssistent.
What ended the problem?+
After a restart and a move into a separate virtual network it did not recur. According to IT-Connect the behavior is said to return once the device regains internet access. The owner disconnected the machine from the Wi-Fi for good.