# CVE-2026-34205: Home Assistant: Unauthenticated App (Add-on) Endpoints Exposed to Local Network via Host Network Mode

> Attackers on the local network can access unauthenticated Home Assistant app endpoints when host network mode is enabled, bypassing intended access restrictions.

- **Severity:** Critical 9.7 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Mar 2026
- **Updated:** 1 Apr 2026

## What is CVE-2026-34205?

CVE-2026-34205 is a critical missing authorization vulnerability in home-assistant Home Assistant Operating System, published on 27 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Home Assistant is open source home automation software that puts local control and privacy first. Home Assistant apps (formerly add-ons) configured with host network mode expose unauthenticated endpoints bound to the internal Docker bridge interface to the local network. On Linux, this configuration does not restrict access to the app as intended, allowing any device on the same network to reach these endpoints without authentication. Home Assistant Supervisor 2026.03.02 addresses the issue.

Weakness: CWE-923 (Improper Restriction of Communication Channel to Intended Endpoints)

## Which versions are affected by CVE-2026-34205?


## How do I fix CVE-2026-34205?

No fix has been published for CVE-2026-34205 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34205 being exploited?

There is no known exploitation of CVE-2026-34205 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34205 and fix it if it is affected.

What it is: CVE-2026-34205 is a critical missing authorization vulnerability in home-assistant Home Assistant Operating System, published on 27 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-34205 in the wild and no public exploit code.

Affected product: home-assistant Home Assistant Operating System. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34205/ (Markdown: https://insights.sbomify.com/CVE-2026-34205/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34205
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34205
- OSV: https://osv.dev/vulnerability/CVE-2026-34205

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34205/
Summaries are generated and may contain mistakes; the official description above is the record.