# ESPHome Device Builder: Renamed auth env vars silently disable dashboard authentication on upgrade

Advisory record · `GHSA-rrxg-g2pf-6hh4`

- **Identifiers:** `GHSA-rrxg-g2pf-6hh4` · `CVE-2026-59178` · `PYSEC-2026-4049`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-306](https://cwe.mitre.org/data/definitions/306.html)
- **Tags:** [Authentication bypass](https://agentprime.io/advisories/tag/auth-bypass.md)
- **Published:** 14 Sept 2026
- **Updated:** 1 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 14 Sept 2026, 18:08 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `esphome-device-builder` (PyPI): affected `<1.0.12`; fixed in `1.0.12`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> The esphome-device-builder package before 1.0.12 drops dashboard authentication when operators upgrade and had set the older bare USERNAME and PASSWORD environment variables, which were renamed to ESPHOME_USERNAME and ESPHOME_PASSWORD without a fallback. An unauthenticated client with network access to the dashboard port can then manage devices, including editing configurations and flashing firmware. Upgrade to 1.0.12, which accepts the bare names again as a deprecated fallback; until then, set the ESPHOME_USERNAME and ESPHOME_PASSWORD variables to the same values.

Written 1 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0078, the 56th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:09 UTC: First seen by agentprime
- 31 Oct 2026, 14:09 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-rrxg-g2pf-6hh4)

## Sources

- [GitHub Advisory Database: GHSA-rrxg-g2pf-6hh4](https://github.com/advisories/GHSA-rrxg-g2pf-6hh4)
- [OSV: GHSA-rrxg-g2pf-6hh4](https://osv.dev/vulnerability/GHSA-rrxg-g2pf-6hh4)
- <https://github.com/esphome/device-builder/security/advisories/GHSA-rrxg-g2pf-6hh4>
- <https://github.com/esphome/device-builder/pull/1625>
- <https://github.com/esphome/device-builder/commit/9e294f729c3eb7334bb57b9fc49b75b728052f52>
- <https://github.com/esphome/device-builder>
- <https://github.com/esphome/device-builder/releases/tag/1.0.12>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-rrxg-g2pf-6hh4>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-rrxg-g2pf-6hh4/>. Everything for agents: <https://agentprime.io/llms.txt>.