CVE-2026-39932 in OpenEMR
Summary
by MITRE • 08/03/2026
OpenEMR through 8.2.0 contains a remote code execution vulnerability in the document category tree component (library/classes/Tree.class.php) that allows authenticated administrators to execute arbitrary operating system commands by injecting PHP payloads into the categories database table. Attackers can chain arbitrary SQL execution to alter the id column type to VARCHAR and insert a malicious PHP payload, which is then executed via an unsanitized eval() call whenever any page instantiates CategoryTree, including unauthenticated and low-privilege pages, resulting in command execution as the web server user.
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Analysis
by VulDB Data Team • 08/03/2026
This vulnerability represents a critical remote code execution flaw in OpenEMR versions up to 8.2.0 that stems from improper input validation and insecure coding practices within the document category tree component. The issue resides in library/classes/Tree.class.php where an unsanitized eval() call processes data from the categories database table without adequate sanitization or validation. The vulnerability requires authentication as an administrator but can result in full system compromise when exploited, as it allows attackers to execute arbitrary operating system commands with the privileges of the web server user.
The technical exploitation involves a multi-step attack chain that begins with SQL injection capabilities to modify the database schema. Attackers can alter the id column type from its expected data type to VARCHAR, which enables them to inject malicious PHP payloads directly into the database. This modification creates a persistent backdoor that remains active until the database is manually repaired or the application is updated. The vulnerability is particularly dangerous because the malicious code executes whenever any page instantiates CategoryTree, meaning that even unauthenticated users or those with minimal privileges can trigger the execution of attacker-controlled PHP code through normal application usage patterns.
The operational impact extends beyond simple command execution to encompass complete system compromise and potential data exfiltration. Since the vulnerability affects components used across multiple pages including those accessible to low-privilege users, an attacker could potentially gain unauthorized access to sensitive patient data, modify medical records, or establish persistent access to the healthcare information system. The attack vector is particularly concerning in healthcare environments where compliance with regulations such as HIPAA requires strict controls over data access and system integrity, making this vulnerability a significant risk for organizations handling protected health information.
Security mitigations should include immediate patching of affected OpenEMR installations to version 8.2.1 or later, which contains the necessary fixes for the vulnerable eval() call and input validation issues. Organizations should also implement database schema monitoring to detect unauthorized modifications to critical table structures and apply principle of least privilege access controls to limit administrator account usage. Additional defensive measures include implementing web application firewalls to monitor for suspicious SQL injection patterns, conducting regular security audits of database contents, and ensuring proper input sanitization throughout the application codebase. This vulnerability aligns with CWE-94 (Improper Control of Generation of Code) and represents a classic example of insecure deserialization combined with inadequate input validation that enables arbitrary code execution through database manipulation.
The attack pattern demonstrates characteristics consistent with MITRE ATT&CK framework techniques including T1059.007 (Command and Scripting Interpreter: PowerShell) and T1190 (Exploit Public-Facing Application) where attackers leverage authenticated access to exploit application vulnerabilities. The persistence mechanism through database modification makes this vulnerability particularly difficult to detect through standard network monitoring, as the malicious code operates within legitimate application processes rather than creating suspicious network connections or file system activities. Organizations should also consider implementing database activity logging and anomaly detection systems to identify unauthorized schema modifications that could indicate exploitation attempts.