CVE-2026-25510 affects ci4ms, a CMS built on the CodeIgniter 4 framework, specifically versions prior to 0.28.5.0. The vulnerability stems from improper validation and restriction on file uploads, allowing authenticated users with file editor permissions to upload files containing malicious PHP code. This is categorized under CWE-434 (Unrestricted Upload of File with Dangerous Type) and CWE-94 (Improper Control of Generation of Code). By exploiting the file creation and save endpoints, an attacker can upload and execute arbitrary PHP scripts on the server, leading to remote code execution (RCE). The vulnerability requires the attacker to have authenticated access with file editor privileges, but no additional user interaction is necessary. The CVSS 3.1 base score is 10.0, reflecting the vulnerability's critical nature with network attack vector, low attack complexity, privileges required, no user interaction, and complete compromise of confidentiality, integrity, and availability. Although no public exploits have been reported yet, the vulnerability's characteristics make it highly exploitable in environments where ci4ms is deployed. The issue was addressed in version 0.28.5.0 by implementing proper file type validation and restricting executable file uploads. Organizations running affected versions should prioritize upgrading to the patched release to mitigate the risk of full system compromise.

The impact of this vulnerability on European organizations can be severe. Successful exploitation allows attackers to execute arbitrary code on the web server hosting ci4ms, potentially leading to full system compromise, data theft, defacement, or use of the server as a pivot point for further attacks within the network. Confidentiality is at risk as attackers can access sensitive data stored or processed by the CMS. Integrity is compromised since attackers can modify or inject malicious content or code. Availability is also threatened due to potential denial-of-service conditions caused by malicious payloads or system instability. Given ci4ms is a CMS, it may be used by various organizations including SMEs, public sector entities, and enterprises for content management and ERP integration. The risk is heightened in sectors with sensitive data or critical operations, such as finance, healthcare, and government. The requirement for authenticated access somewhat limits exposure but does not eliminate risk, especially if credential theft or insider threats are possible. European organizations relying on ci4ms without timely patching face a critical security risk that could lead to significant operational disruption and regulatory consequences under GDPR if personal data is compromised.

1. Immediately upgrade ci4ms installations to version 0.28.5.0 or later, where the vulnerability is patched. 2. Restrict file editor permissions strictly to trusted users and review existing user roles to minimize the number of users with such privileges. 3. Implement additional file upload validation at the web server or application firewall level to block executable file types, particularly PHP scripts. 4. Employ web application firewalls (WAFs) with rules designed to detect and block attempts to upload or execute unauthorized code. 5. Monitor logs for suspicious file upload activity or unusual execution patterns indicative of exploitation attempts. 6. Enforce strong authentication mechanisms, including multi-factor authentication, to reduce risk of credential compromise. 7. Conduct regular security audits and penetration testing focused on file upload functionality. 8. Isolate the CMS environment using containerization or network segmentation to limit lateral movement if compromise occurs. 9. Backup critical data regularly and verify restoration procedures to ensure resilience against potential attacks. 10. Educate administrators and developers about secure file handling practices and the risks of unrestricted file uploads.