CVE-2026-3726
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on Tenda F453 routers by exploiting a stack-based buffer overflow in the webExcptypemanFilter function. Attackers can trigger this by manipulating the 'page' argument in HTTP requests. All users running the affected firmware version are at risk.
💻 Affected Systems
- Tenda F453
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise leading to persistent remote access, network traffic interception, lateral movement to other devices, and potential botnet recruitment.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind strict firewall rules, but still vulnerable to internal threats.
🎯 Exploit Status
Exploit details are publicly available on GitHub, making weaponization probable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda website for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Tenda F453 routers from critical networks and internet exposure
Access Control Lists
allRestrict access to router management interface to trusted IP addresses only
🧯 If You Can't Patch
- Replace vulnerable devices with patched or different models
- Implement strict network monitoring for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface; if version is 1.0.0.3, device is vulnerable.Check Version:
Check via router web interface or SSH if enabled: cat /proc/version or similar firmware version commandVerify Fix Applied:
Verify firmware version has been updated to a version later than 1.0.0.3.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to /goform/webExcptypemanFilter with manipulated page parameter
- Multiple failed exploitation attempts
Network Indicators:
- HTTP traffic to router management interface with abnormal payload sizes
- Suspicious outbound connections from router
SIEM Query:
source_ip=router_ip AND (url_path="/goform/webExcptypemanFilter" OR http_method="POST") AND content_length>normal_threshold