CVE-2026-124489 in OpenEMR
Summary
by MITRE • 11/08/2026
OpenEMR before 8.3.0 contains a broken access control vulnerability in portal/portal_payment.php that allows low-privilege authenticated users to bypass billing ACL checks by tampering patient identifiers. Attackers can modify the pid and form_pid parameters to view payment pages and record fraudulent payment receipts for arbitrary patients, corrupting billing records.
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Analysis
by VulDB Data Team • 11/08/2026
The identified vulnerability in OpenEMR versions prior to 8.3.0 represents a critical failure in server-side access control mechanisms within the patient portal module. Specifically, the flaw resides in the file portal/portal_payment.php and is classified under CWE-269 Improper Privilege Management or more precisely CWE-639 Authorization Bypass Through User-Controlled Key. This type of vulnerability occurs when an application relies on client-supplied data to determine access rights without performing adequate server-side validation against authoritative identity stores. In this context, the application incorrectly assumes that possession of a valid session for a low-privilege authenticated user grants permission to view or manipulate billing information associated with any patient identifier provided in the request parameters.
The technical mechanism of exploitation involves manipulating two specific HTTP parameters: pid and form_pid. These identifiers are intended to restrict access to payment records belonging exclusively to the currently logged-in patient. However, due to insufficient validation logic, an attacker can simply alter these values to point toward a different patient's unique identifier within the database. Because the application does not cross-reference the provided patient ID with the authenticated user's actual assigned patient list or role permissions before rendering the payment interface, it proceeds to load and display sensitive financial data for arbitrary patients. This bypasses the intended Access Control List checks that should enforce strict separation between patient records based on ownership and authorization levels.
The operational impact of this vulnerability is severe from both a privacy and integrity perspective. By exploiting this flaw, an attacker with low-privilege access can view confidential payment histories, transaction amounts, and billing details for any other user in the system. This constitutes a significant breach of patient confidentiality under regulations such as HIPAA or GDPR. Furthermore, the ability to generate fraudulent payment receipts allows attackers to corrupt financial records by creating fake transactions that appear legitimate within the system's reporting structures. This not only compromises data integrity but can also lead to substantial financial discrepancies and audit failures for healthcare providers relying on OpenEMR for their billing operations.
To mitigate this vulnerability, immediate patching is required as it was resolved in version 8.3.0 of OpenEMR. Administrators should upgrade the application immediately if they are running any earlier release. In scenarios where upgrading is not immediately feasible, a temporary mitigation involves implementing strict server-side validation that verifies every requested patient identifier against an authoritative list of patients associated with the authenticated user's session or role before processing any billing-related requests. Additionally, deploying a Web Application Firewall rule to detect and block anomalous patterns in pid parameter manipulation may provide limited protection until the code is patched. This incident highlights the importance of implementing robust authorization checks that rely on server-side state rather than client-supplied identifiers for sensitive operations involving financial data.