Home Assistant MCP Server unauthenticated access to YAML backups

Severity: medium · CVSS 6.5 · Published 2026-05-14

The Home Assistant MCP Server integration, which allows AI models to interact with Home Assistant, contains a vulnerability where configuration backups are stored in a publicly accessible folder. If the YAML editing feature is enabled, any user on the same network can download these backups without a password. These files often contain sensitive information such as plaintext passwords for smart home services, security credentials, and private location coordinates.

Technologies: ha-mcp (PyPI). Vendors: PyPI.

Quick answers

Is This vulnerability exploited in the wild?
No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?
Medium severity, with a CVSS score of 6.5, published 14 May 2026.
Which products and versions are affected?
ha-mcp (PyPI) < 7.5.0.
Is there a fix for This vulnerability?
A patch was published on 2026-05-14: Fixed in version 7.5.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?
It is attacked from the adjacent network, in a software library.
Am I affected?
Check whether you run ha-mcp (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is classified as CWE-552 (Files or Directories Accessible to External Parties). When 'ENABLE_YAML_CONFIG_EDITING' is set to true, the 'ha_config_set_yaml' function saves backups to the 'www/yaml_backups/' directory. By design, Home Assistant serves the 'www/' directory at the '/local/' endpoint without authentication to facilitate static dashboard assets. An attacker on the local network (or internet if the instance is exposed) can guess or discover the backup filenames—which use a predictable timestamp format—and download them without credentials. These backups typically contain sensitive data like MQTT passwords and REST credentials. The issue is fixed in version 7.5.0 by moving backups to a non-public directory and migrating existing files.

Affected products

  • homeassistant-ai ha-mcp < 7.5.0

Timeline

  • 2026-05-08: disclosed: Vulnerability reported and published to repository advisory database.
  • 2026-05-14: advisory: GitHub Advisory GHSA-g39v-cvjh-8fpf published.
  • 2026-05-14: patched: Fixed in version 7.5.0.

References

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