CVE-2026-2146
📋 TL;DR
This vulnerability allows remote attackers to upload arbitrary files without restrictions through the updateAvatar function in guchengwuyue yshopmall. Attackers can exploit this to upload malicious files, potentially leading to server compromise. All users running yshopmall version 1.9.1 or earlier are affected.
💻 Affected Systems
- guchengwuyue yshopmall
📦 What is this software?
Yshopmall by Guchengwuyue
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment
Likely Case
Webshell upload allowing persistent backdoor access and data exfiltration
If Mitigated
File upload limited to authenticated users with proper file type validation and storage outside web root
🎯 Exploit Status
Exploit details publicly available in GitHub issues; manipulation of File argument leads to unrestricted upload
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: No
Instructions:
No official patch available. Monitor GitHub repository for updates. Consider applying community fixes if available.
🔧 Temporary Workarounds
Web Application Firewall Rule
allBlock or restrict access to /api/users/updateAvatar endpoint
WAF specific - configure rule to block POST requests to /api/users/updateAvatar
File Upload Restriction
allImplement server-side file type validation and size limits
Application specific - modify FileUtil to validate file extensions and MIME types
🧯 If You Can't Patch
- Disable the updateAvatar functionality completely
- Implement network segmentation to isolate yshopmall from critical systems
🔍 How to Verify
Check if Vulnerable:
Check if running yshopmall version 1.9.1 or earlier. Test by attempting to upload a file with malicious extension to /api/users/updateAvatarCheck Version:
Check application version in configuration files or admin panelVerify Fix Applied:
Verify file upload restrictions are enforced and only allowed file types can be uploaded📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads to /api/users/updateAvatar
- Uploads of executable files (php, jsp, asp, etc.)
- Large number of upload requests
Network Indicators:
- POST requests to /api/users/updateAvatar with suspicious file names
- Traffic patterns indicating file upload exploitation
SIEM Query:
source="web_server" AND uri="/api/users/updateAvatar" AND (file_extension="php" OR file_extension="jsp" OR file_extension="asp")