---
title: "CVE-2026-59178: ESPHome Device Builder: Renamed auth env vars silently disable dashboard authentication on upgrade"
url: https://erroneo.us/security/cve/CVE-2026-59178/
description: "CVE-2026-59178 (esphome-device-builder (PyPI)): ESPHome Device Builder Dashboard is a dashboard for the ESPHome home management software. Prior to version…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-09-14
date_modified: 2026-09-14
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-59178"
kev: false
cvss: 9.8
epss: 0.00779
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-59178: ESPHome Device Builder: Renamed auth env vars silently disable dashboard authentication on upgrade

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.8% , percentile 55: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 55% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes esphome-device-builder (PyPI) < 1.0.12, fixed in 1.0.12 . Check your lockfile, including transitive dependencies.

## What it is

ESPHome Device Builder Dashboard is a dashboard for the ESPHome home management software. Prior to version 1.0.12, the dashboard reads its authentication credentials from $ESPHOMEUSERNAME and $ESPHOMEPASSWORD. Earlier versions, and the legacy esphome dashboard, read the bare $USERNAME and $PASSWORD instead. When the env vars were renamed the bare names were dropped with no fallback, so an operator who had protected their dashboard with USERNAME / PASSWORD (as the older getting started guide documented) loses authentication on upgrade and the dashboard starts open to anyone who can reach its port. The issue is fixed in 1.0.12. The bare $USERNAME / $PASSWORD are accepted again as a deprecated fallback so previously protected instances stay protected across the upgrade without operator intervention, with a loud deprecation warning at startup directing operators to rename them to $ESPHOMEUSERNAME / $ESPHOMEPASSWORD. The fallback is gated on $PASSWORD being set and is only adopted as a pair, so the OS provided $USERNAME is never read on its own and the original collision footgun stays closed. A lone bare $PASSWORD with no username still fails loud as a credential mismatch rather than starting unauthenticated. This restores compatibility rather than failing closed on the legacy names, because the priority is that an instance which was protected before the upgrade stays protected without the operator having to act; the deprecation warning plus a future removal handles the migration. Operators should migrate to the $ESPHOME names. The esphome container delivers the fix in the 2026.6.2 release, which bumps its pinned esphome-device-builder version to 1.0.12. Without upgrading, restore authentication immediately by setting the new env vars to the same values, on any affected version. Alternatively, do not expose the dashboard port to untrusted networks, and check the startup logs for the WITHOUT AUTHENTICATION banner to confirm whether a given instance is currently open.

## Affected packages

- PyPI `esphome-device-builder` < 1.0.12 → fixed: 1.0.12

## Affected products (CVE record)

- esphome device-builder: < 1.0.12

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.78% probability of exploitation activity in the next 30 days; percentile 55.

## Sources

- [GitHub Advisory GHSA-rrxg-g2pf-6hh4](https://github.com/advisories/GHSA-rrxg-g2pf-6hh4)
- [CVE.org record CVE-2026-59178](https://www.cve.org/CVERecord?id=CVE-2026-59178)
- [NVD entry CVE-2026-59178](https://nvd.nist.gov/vuln/detail/CVE-2026-59178)
- [github.com](https://github.com/esphome/device-builder/security/advisories/GHSA-rrxg-g2pf-6hh4)
- [github.com](https://github.com/esphome/device-builder/pull/1625)
- [github.com](https://github.com/esphome/device-builder/commit/9e294f729c3eb7334bb57b9fc49b75b728052f52)
- [github.com](https://github.com/esphome/device-builder/releases/tag/1.0.12)

---
Source page: https://erroneo.us/security/cve/CVE-2026-59178/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt