Auth bypass in Kreaweb Genealogy
CVE-2026-39355
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.
Vulnerability class: Broken Access Control
EPSS: 0.003 (23.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Kreaweb Genealogy
- Mgeurts Genealogy — versions < 5.9.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-39355?
- CVE-2026-39355 is a critical-severity vulnerability in Kreaweb Genealogy, classified under Missing Authorization. CVSS score: 9.9/10. Published 2026-04-07.
- How severe is CVE-2026-39355?
- Critical severity. CVSS v3 base score is 9.9 out of 10.