CVE-2025-52998 is a deserialization vulnerability classified under CWE-502 affecting Chamilo LMS, a widely used open-source learning management system. Versions prior to 1.11.30 perform insecure deserialization of data, allowing attackers to supply malicious serialized objects. This flaw enables attackers to instantiate arbitrary classes with fully controlled properties, which can alter the application's internal logic and behavior. Such manipulation can lead to unauthorized code execution, privilege escalation, or data tampering within the web application context. The vulnerability is exploitable remotely over the network without user interaction but requires the attacker to have high privileges, indicating some level of authentication or elevated access is needed. The CVSS 4.0 score of 7 reflects high severity due to the potential impact on confidentiality, integrity, and availability, combined with relatively low attack complexity and no user interaction. The issue was publicly disclosed in March 2026 and has been patched in Chamilo LMS version 1.11.30. No known exploits have been reported in the wild yet, but the vulnerability poses a significant risk to organizations relying on vulnerable versions of Chamilo LMS for their educational platforms.

The vulnerability allows attackers to manipulate the logic of Chamilo LMS by injecting malicious serialized objects, potentially leading to unauthorized access, data modification, or disruption of service. This can compromise sensitive educational data, user credentials, and course content integrity. Organizations using vulnerable versions may face data breaches, loss of trust, and operational downtime. Since Chamilo LMS is used globally in educational institutions, the impact extends to students, educators, and administrators, potentially affecting learning continuity. The requirement for high privileges to exploit somewhat limits the attack surface but does not eliminate risk, especially in environments with weak internal controls or compromised accounts. The absence of known exploits currently reduces immediate threat but does not preclude future attacks, making timely patching critical.

Organizations should immediately upgrade Chamilo LMS installations to version 1.11.30 or later, where the deserialization vulnerability is patched. Additionally, implement strict input validation and avoid deserializing untrusted data wherever possible. Employ application-layer firewalls to monitor and block suspicious serialized payloads. Restrict access to the LMS backend to trusted users and networks, enforcing strong authentication and role-based access controls to minimize the risk of privilege escalation. Conduct regular security audits and code reviews focusing on serialization/deserialization logic. Enable logging and monitoring to detect anomalous activities related to object deserialization. Educate administrators about the risks of deserialization vulnerabilities and the importance of timely patch management. Finally, consider deploying runtime application self-protection (RASP) tools that can detect and block malicious deserialization attempts in real time.