CVE-2026-39355·PHP vulnerability
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.
- Severity
- critical
- Software
- PHP
- Fixed in
- 5.9.1
- Published
- 2026-04-07
Affected versions
Until: 5.9.1
Fixed in: 5.9.1
How to fix this CVE
Upgrade the Genealogy PHP application to version 5.9.1 or later to patch a critical authorization bypass that allows authenticated users to assume control of team workspaces. This vulnerability permits unauthorized access to sensitive genealogy data and requires immediate patching in production environments. After upgrading, verify that team ownership transfers are restricted to authorized administrators only.
sudo dnf update phpDefensia detects this vulnerability
How to check if you are affected
- Step 1: Check PHP version installed: php -v and verify the Genealogy application version with grep -r 'version' /path/to/genealogy/config or check the application's admin panel
- Step 2: Query the database to identify team ownership records: SELECT user_id, team_id, owner_id FROM teams; to spot mismatched or suspicious ownership changes
- Step 3: Search application logs for unauthorized team transfer operations: grep -i 'transfer\|ownership\|team.*change' /path/to/genealogy/logs/ for timestamps outside normal maintenance windows
- Step 4: After patching, verify fix by attempting to transfer a test team with a non-owner authenticated account—the operation should be rejected with a permission denied error
FAQ
What is CVE-2026-39355?
This is a broken access control flaw in Genealogy PHP applications prior to 5.9.1 that allows any authenticated user to hijack ownership of team workspaces belonging to other users, granting them full access to all associated genealogy records and data.
Is CVE-2026-39355 being actively exploited?
No, this vulnerability is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available, though organizations should still prioritize patching due to its critical severity and ease of exploitation by insider threats.
What versions of PHP are affected by CVE-2026-39355?
All versions of the Genealogy PHP application prior to version 5.9.1 are vulnerable; the exact earliest affected version is unknown but likely spans multiple releases.
How do I check if my server is vulnerable to CVE-2026-39355?
Run php -v to check PHP version and verify your Genealogy application version by checking the application's configuration files or admin interface; if it is below 5.9.1, your system is vulnerable.
Does Defensia detect CVE-2026-39355?
Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If PHP is installed on a monitored server, CVE-2026-39355 will appear in your dashboard with remediation steps.
Related PHP CVEs
References
Track CVEs across your fleet automatically
Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2026-39355. Free for 1 server.
Get started free