# CVE-2026-28766: Gardyn Cloud API Missing Authentication for Critical Function

> Unauthenticated attackers can access all registered user account information via a specific Gardyn Cloud API endpoint.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Apr 2026
- **Updated:** 7 Apr 2026
- **Also known as:** GHSA-m7jc-wgg6-fhj3

## What is CVE-2026-28766?

CVE-2026-28766 is a critical missing authorization vulnerability in Gardyn Cloud API, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A specific endpoint exposes all user account information for registered Gardyn users without requiring authentication.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-28766?

It affects 1 product.


Products: Mygardyn Cloud Api.

## How do I fix CVE-2026-28766?

No fix has been published for CVE-2026-28766 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-28766 being exploited?

There is no known exploitation of CVE-2026-28766 in the wild and no public exploit code.

Public exploit code:

- CVE-2026-28766: Missing Authentication on User Account Endpoint — Gardyn Home Kit (ICSA-26-055-03) (github_poc): https://github.com/MichaelAdamGroberman/CVE-2026-28766

## Other vulnerabilities in Gardyn Cloud API

- [CVE-2026-25197](https://insights.sbomify.com/CVE-2026-25197/): Gardyn Cloud API Authorization Bypass Through User-Controlled Key (critical 9.3)
- [CVE-2026-32646](https://insights.sbomify.com/CVE-2026-32646/): Gardyn Cloud API Missing Authentication for Critical Function (high 8.7)
- [CVE-2026-28767](https://insights.sbomify.com/CVE-2026-28767/): Gardyn Cloud API Missing Authentication for Critical Function (medium 6.9)
- [CVE-2026-32662](https://insights.sbomify.com/CVE-2026-32662/): Gardyn Cloud API Active Debug Code (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28766 and fix it if it is affected.

What it is: CVE-2026-28766 is a critical missing authorization vulnerability in Gardyn Cloud API, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-28766 in the wild and no public exploit code.

Affected product: Gardyn Cloud API. 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-2026-28766/ (Markdown: https://insights.sbomify.com/CVE-2026-28766/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28766
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28766
- OSV: https://osv.dev/vulnerability/CVE-2026-28766

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28766/
Summaries are generated and may contain mistakes; the official description above is the record.