# CVE-2026-39355: Missing authorization in genealogy

> An authenticated user can hijack any team by transferring ownership, gaining unrestricted access to associated genealogy data.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-2rq7-jqm7-w8x4

## What is CVE-2026-39355?

CVE-2026-39355 is a critical missing authorization vulnerability in MGeurts genealogy, published on 7 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Genealogy is a family tree PHP application. Prior to 5.9.1, a critical broken access control vulnerability in the genealogy application allows any authenticated user to transfer ownership of arbitrary non-personal teams to themselves. This enables complete takeover of other users’ team workspaces and unrestricted access to all genealogy data associated with the compromised team. This vulnerability is fixed in 5.9.1.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-39355?

It affects 1 product.


Products: Kreaweb Genealogy.

## How do I fix CVE-2026-39355?

No fix has been published for CVE-2026-39355 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-39355 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39355 exists.

## Other vulnerabilities in MGeurts genealogy

- [CVE-2025-55287](https://insights.sbomify.com/CVE-2025-55287/): Genealogy has a stored XSS vulnerability (high 8.0)
- [CVE-2025-55288](https://insights.sbomify.com/CVE-2025-55288/): Genealogy has a Reflected XSS Vulnerability (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-39355 and fix it if it is affected.

What it is: CVE-2026-39355 is a critical missing authorization vulnerability in MGeurts genealogy, published on 7 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39355 exists.

Affected product: MGeurts genealogy. 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-2026-39355/ (Markdown: https://insights.sbomify.com/CVE-2026-39355/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-39355
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-39355
- OSV: https://osv.dev/vulnerability/CVE-2026-39355

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-39355/
Summaries are generated and may contain mistakes; the official description above is the record.