CVE-2026-2146 is a vulnerability identified in the guchengwuyue yshopmall e-commerce platform, affecting versions 1.9.0 and 1.9.1. The flaw exists in the updateAvatar function within the /api/users/updateAvatar endpoint, specifically in the co.yixiang.utils.FileUtil component responsible for handling file uploads. The vulnerability arises due to insufficient validation and sanitization of the File argument, allowing an attacker to upload arbitrary files without restrictions. This unrestricted upload capability can be exploited remotely by an attacker with limited privileges (PR:L), without requiring any user interaction (UI:N) or authentication tokens (AT:N). The CVSS 4.0 score of 5.3 reflects a medium severity, considering the ease of exploitation (low attack complexity) and the potential for partial impact on confidentiality, integrity, and availability. The exploit code has been publicly disclosed, increasing the likelihood of attacks, although no active exploitation has been reported yet. The vendor has been notified but has not issued a patch or mitigation guidance. This vulnerability could allow attackers to upload malicious scripts or executables, potentially leading to remote code execution, data breaches, or service disruption. The lack of scope change (S:N) indicates the impact is confined to the vulnerable component or application context. The absence of security controls (SC:N) further exacerbates the risk. Given the nature of the vulnerability, it is critical for organizations using yshopmall to assess their exposure and implement immediate controls.

For European organizations, this vulnerability poses a significant risk to the security of e-commerce platforms running yshopmall versions 1.9.0 and 1.9.1. Successful exploitation could allow attackers to upload malicious files such as web shells or malware, leading to unauthorized access, data theft, or disruption of services. This can compromise customer data confidentiality and integrity, damage brand reputation, and result in financial losses due to downtime or regulatory penalties under GDPR. The medium severity score reflects that while the vulnerability does not require user interaction or complex attack vectors, it does require some level of privilege, which may limit exposure to internal or authenticated users. However, if the affected endpoint is accessible publicly or through weak authentication, the risk escalates. The public availability of exploit code increases the urgency for mitigation. European organizations in retail, supply chain, or service sectors relying on yshopmall could face targeted attacks, especially if they have not implemented compensating controls. The vulnerability also raises concerns about compliance with data protection regulations, as unauthorized file uploads could lead to data breaches.

1. Immediately restrict access to the /api/users/updateAvatar endpoint to trusted and authenticated users only, enforcing the principle of least privilege. 2. Implement strict server-side validation and sanitization of all uploaded files, including checking file type, size, and content to prevent malicious payloads. 3. Employ allow-listing of permitted file extensions and MIME types, rejecting all others. 4. Use secure storage locations for uploaded files, outside of the web root, to prevent direct execution. 5. Monitor logs and network traffic for unusual upload activity or access patterns to detect potential exploitation attempts. 6. Apply web application firewalls (WAF) with rules targeting unrestricted upload attempts. 7. Engage with the vendor or community to obtain or develop patches and update to a fixed version once available. 8. Conduct regular security assessments and penetration testing focusing on file upload functionalities. 9. Educate development teams on secure coding practices related to file handling. 10. If immediate patching is not possible, consider disabling the avatar upload feature temporarily to reduce risk.