CVE-2026-25510 is a critical security vulnerability identified in ci4ms, a modular CMS built on the CodeIgniter 4 framework. The vulnerability arises from an unrestricted file upload flaw (CWE-434) combined with the ability to execute uploaded code (CWE-94). Specifically, authenticated users with file editor permissions can exploit the file creation and save endpoints to upload malicious PHP files. These files can then be executed on the server, resulting in Remote Code Execution (RCE). The vulnerability affects all ci4ms versions prior to 0.28.5.0, where the issue has been patched. The attack vector requires network access and valid credentials with file editing rights but does not require additional user interaction, making it highly exploitable in environments where such permissions are granted. The CVSS v3.1 base score is 10.0, reflecting the vulnerability's critical impact on confidentiality, integrity, and availability, as it allows an attacker to fully compromise the affected system. Although no known exploits have been reported in the wild, the vulnerability's nature and ease of exploitation make it a significant threat. The modular architecture and RBAC system in ci4ms suggest that improper permission management could exacerbate the risk. The vulnerability highlights the importance of strict validation and sanitization of uploaded files, especially in web applications that allow file management by authenticated users.

For European organizations, this vulnerability poses a severe risk, particularly for those using ci4ms as part of their web content management or ERP systems. Successful exploitation can lead to full system compromise, data breaches, defacement, or disruption of services. Confidential data stored or processed by the CMS could be exposed or altered, impacting privacy compliance such as GDPR. The integrity of business processes relying on the CMS could be undermined, and availability could be disrupted through malicious payloads or backdoors. Organizations with publicly accessible administrative interfaces or weak internal network segmentation are especially vulnerable. The critical severity and ease of exploitation mean that attackers with minimal privileges can escalate to full control, potentially enabling lateral movement within corporate networks. This could also facilitate supply chain attacks if the CMS is used to manage content or software distribution. The absence of known exploits in the wild currently offers a window for proactive mitigation before widespread attacks occur.

1. Immediately upgrade all ci4ms installations to version 0.28.5.0 or later, where the vulnerability is patched. 2. Review and tighten RBAC policies to ensure that only trusted users have file editor permissions. 3. Implement strict file upload validation and sanitization, restricting allowed file types to safe formats and blocking executable files such as PHP. 4. Employ web application firewalls (WAFs) with rules to detect and block suspicious file upload attempts and execution patterns. 5. Monitor logs for unusual file upload activities and unexpected PHP file creations in upload directories. 6. Segment the network to isolate CMS administrative interfaces from the broader corporate network, limiting potential lateral movement. 7. Conduct regular security audits and penetration tests focusing on file upload functionalities. 8. Educate administrators and developers about secure file handling practices and the risks of excessive permissions. 9. If immediate upgrade is not feasible, consider disabling file upload features temporarily or restricting access to the CMS backend via IP whitelisting or VPN. 10. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.