CVE-2026-39355: Genealogy is Missing Authorization in `TeamController::transferOwnership()` Allows Any Authenticated User to Hijack Any Team (Broken Access Control)

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-04-07 · updated 2026-07-24
Weakness: CWE-862

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.

Affected products

MGeurts genealogy: before 5.9.1 — fixed in 5.9.1

How to fix

Upgrade to a fixed version: MGeurts genealogy 5.9.1. Check the vendor advisory for mitigations.

References

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