CVE-2026-2146 is a vulnerability identified in the guchengwuyue yshopmall e-commerce platform, affecting versions 1.9.0 and 1.9.1. The issue resides in the updateAvatar function within the /api/users/updateAvatar endpoint, specifically in the co.yixiang.utils.FileUtil component. The vulnerability arises due to insufficient validation or restrictions on the File argument, allowing an attacker to upload arbitrary files without restrictions. This unrestricted upload flaw can be exploited remotely without requiring authentication or user interaction, making it highly accessible to attackers. The uploaded files could be malicious scripts or executables, potentially enabling remote code execution, privilege escalation, or persistent backdoors on the affected system. Despite early reporting, the vendor has not issued a patch or official response, and public exploit code has been released, increasing the likelihood of exploitation in the wild. The CVSS 4.0 base score of 5.3 reflects a medium severity, considering the ease of exploitation and potential impact on confidentiality, integrity, and availability. The lack of scope change and no requirement for user interaction or privileges further characterize the vulnerability. This flaw poses a significant risk to organizations relying on yshopmall for their e-commerce operations, as attackers could compromise servers, steal sensitive data, or disrupt services.

The unrestricted file upload vulnerability in yshopmall can have severe consequences for affected organizations. Attackers can upload malicious payloads such as web shells, ransomware, or malware, leading to remote code execution and full system compromise. This can result in data breaches, unauthorized access to customer information, financial loss, and damage to brand reputation. Additionally, attackers could leverage compromised systems as pivot points for lateral movement within corporate networks, escalating the impact. The vulnerability's remote exploitability without authentication lowers the barrier for attackers, increasing the risk of widespread exploitation, especially given the public availability of exploit code. Organizations operating e-commerce platforms with sensitive customer data and payment information are particularly at risk. The absence of vendor patches exacerbates the threat, leaving systems exposed for extended periods. Disruption of e-commerce services could also lead to significant operational and revenue losses.

To mitigate CVE-2026-2146, organizations should immediately implement strict input validation and file type restrictions on the updateAvatar endpoint to prevent arbitrary file uploads. Deploy web application firewalls (WAFs) with custom rules to detect and block suspicious upload attempts targeting the vulnerable API. Isolate the file upload functionality in a sandboxed environment with minimal privileges to limit potential damage from malicious files. Monitor server logs and network traffic for unusual upload patterns or execution of unauthorized scripts. If possible, disable the updateAvatar feature temporarily until a vendor patch is available. Conduct thorough code reviews and penetration testing focused on file upload mechanisms. Employ runtime application self-protection (RASP) solutions to detect and block exploitation attempts in real time. Maintain regular backups and ensure incident response plans are updated to handle potential compromises. Engage with the vendor for updates and consider migrating to alternative platforms if remediation is delayed.