---
id: "CVE-2026-77056"
kind: "vulnerability"
aliases: ["CVE-2026-77056"]
title: "boneIO image: Mosquitto broker ships with public default MQTT credentials"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["beaglebone", "boneio", "home-assistant", "infrastructure", "iot", "mosquitto", "mqtt", "self-hosted"]
not_affected_if: ["isolated-network", "version-1.6.0-or-later"]
published_at: "2026-10-26T15:16:43+00:00"
first_seen_at: "2026-10-26T16:02:26+00:00"
updated_at: "2026-10-26T16:03:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77056", "first_seen_at": "2026-10-26T16:02:26+00:00"}]
---

# boneIO image: Mosquitto broker ships with public default MQTT credentials

The boneIO black_debian_images build runs a Mosquitto MQTT broker with the same default username and password on every device, and those credentials are published on GitHub. A remote attacker who logs in can read and write all broker topics, switching connected relays, blinds and gates and injecting fake entities into a linked Home Assistant.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Open the boneIO web panel and look for a warning that MQTT credentials are still the published defaults.
- Check whether the device was installed before `1.6.0`, since upgraded devices keep their old broker credentials.
- Test whether the default broker login is still accepted on the device's MQTT port.

## Fix

- Upgrade the boneIO black_debian_images image to `1.6.0` or later, which generates per-device MQTT passwords at first boot.
- On devices upgraded from earlier versions, change the Mosquitto MQTT password from the boneIO web panel, since the old defaults are kept.

## Timeline

- 2026-10-26T16:02:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-77056

## From the sources

boneIO black_debian_images ships with a Mosquitto MQTT broker that uses the same default credentials on all devices. These credentials are publicly documented on github, and there is no indication in the instructions to change them. A remote attacker can use them to gain full read and write access to the broker, allowing control of connected relays, blinds, and gates, and injection of fake entities into a linked Home Assistant installation.

This issue was fixed in version 1.6.0 of the image: MQTT passwords are generated per device at first boot. Devices upgraded from earlier versions keep their existing broker credentials; from boneio 1.6.0 the web panel reports credentials that are still the published defaults, and the owner has to change them.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_