OpenEMR is a free and open source electronic health records and medical practice management application. Prior to version 8.0.0.3, an Insecure Direct Object Reference (IDOR) vulnerability in the patient portal payment page allows any authenticated portal patient to access other patients' payment records — including invoice/billing data (PHI) and payment card metadata — by manipulating the recid query parameter in portal/portal_payment.php. Version 8.0.0.3 patches the issue.