CVE-2026-4563 is a medium-severity authorization bypass vulnerability affecting MacCMS, a content management system widely used for managing media and e-commerce content. The vulnerability exists in the order_info function located in application/index/controller/User.php, which handles member order details. The root cause is improper validation and authorization checks on the order_id parameter, allowing an attacker to manipulate this argument remotely to access order information without proper permissions. This bypass does not require authentication or user interaction, making it remotely exploitable over the network with low attack complexity. The vulnerability compromises the integrity of access controls, potentially exposing sensitive order data such as purchase details, user information, and transaction history. While no active exploitation has been reported, the availability of a public exploit increases the likelihood of attacks. The vulnerability affects MacCMS versions up to 2025.1000.4052, and no official patches have been linked yet. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, no user interaction, and low impact on confidentiality, integrity, and availability, resulting in a medium overall severity score of 5.3.

The primary impact of CVE-2026-4563 is unauthorized disclosure of sensitive order and user information due to bypassed authorization controls. This can lead to privacy violations, data leakage, and potential misuse of customer data. For organizations, this may result in reputational damage, regulatory non-compliance (especially under data protection laws like GDPR), and financial losses if attackers leverage exposed data for fraud or social engineering. Since the vulnerability allows remote exploitation without authentication, it broadens the attack surface and increases risk. However, the impact on system integrity and availability is minimal, as the vulnerability does not enable modification or disruption of services. Organizations relying on MacCMS for e-commerce or membership management are particularly at risk, as attackers could harvest order details or impersonate users to gain further access.

To mitigate CVE-2026-4563, organizations should first verify if their MacCMS installations are running affected versions up to 2025.1000.4052. Immediate steps include restricting access to the order_info endpoint through network-level controls such as IP whitelisting or VPN access to limit exposure. Implementing web application firewalls (WAFs) with custom rules to detect and block suspicious manipulation of the order_id parameter can reduce exploitation risk. Until an official patch is released, code-level mitigation involves adding strict authorization checks to validate that the requesting user has permission to access the specified order_id. Logging and monitoring access to order_info requests should be enhanced to detect anomalous activities. Organizations should also review user roles and permissions to minimize unnecessary access. Finally, maintain awareness of vendor updates and apply patches promptly once available.