CVE-2025-15426 is a vulnerability identified in the jackying H-ui.admin web administration framework, specifically affecting versions 3.0 and 3.1. The flaw exists in the /lib/webuploader/0.1.5/server/preview.php component, which handles file uploads. Due to insufficient validation or restrictions on uploaded files, attackers can perform unrestricted uploads remotely without any authentication or user interaction. This allows adversaries to upload arbitrary files, which could include web shells or malicious scripts, potentially enabling remote code execution or unauthorized access to the system. The vulnerability has a CVSS 4.0 base score of 6.9, indicating medium severity, with attack vector being network-based, no privileges or user interaction required, and limited impact on confidentiality, integrity, and availability. The vendor was contacted early but did not respond, and no official patches or mitigations have been released. Although no active exploitation has been reported, a public exploit is available, increasing the risk of future attacks. The unrestricted upload flaw is a common vector for web application compromise, often leading to further lateral movement or data breaches if exploited successfully. Organizations using affected versions of H-ui.admin should consider this vulnerability a significant risk due to the ease of exploitation and potential impact on administrative systems.

For European organizations, the impact of CVE-2025-15426 can be significant, especially for those relying on jackying H-ui.admin for managing web applications or internal administrative portals. Successful exploitation could allow attackers to upload malicious files, potentially leading to unauthorized access, data leakage, or service disruption. This could compromise sensitive business data or critical infrastructure components managed through the affected admin interface. The medium severity rating reflects limited direct impact on confidentiality, integrity, and availability, but the unrestricted upload could be leveraged as a foothold for further attacks. Public-facing administrative portals in sectors such as finance, healthcare, manufacturing, and government are particularly at risk. The lack of vendor response and patches increases the window of exposure, raising the likelihood of exploitation attempts. Additionally, the availability of a public exploit lowers the technical barrier for attackers, including cybercriminals and state-sponsored actors targeting European entities. The threat could also affect supply chains if third-party vendors use the vulnerable software, amplifying the risk across interconnected organizations.

Given the absence of official patches, European organizations should implement immediate compensating controls to mitigate CVE-2025-15426. First, deploy web application firewalls (WAFs) with custom rules to detect and block malicious file upload attempts targeting /lib/webuploader/0.1.5/server/preview.php. Second, implement strict server-side validation and filtering of uploaded files, restricting allowed file types and scanning for malware. Third, isolate the affected application environment using network segmentation to limit lateral movement if compromise occurs. Fourth, monitor logs and network traffic for unusual upload activity or execution of unauthorized scripts. Fifth, consider disabling or restricting access to the vulnerable upload functionality if feasible until a patch is available. Sixth, conduct regular security assessments and penetration tests focusing on file upload mechanisms. Finally, maintain an incident response plan tailored to web application compromises and educate administrators about this specific threat. Organizations should also track vendor communications for any future patches or updates and plan for timely application once available.