CVE-2026-2187
📋 TL;DR
This CVE describes a stack-based buffer overflow vulnerability in Tenda RX3 routers. Attackers can remotely exploit this vulnerability by manipulating arguments in the QoS configuration function, potentially leading to arbitrary code execution. Users of Tenda RX3 routers with firmware version 16.03.13.11 are affected.
💻 Affected Systems
- Tenda RX3
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote attackers could execute arbitrary code with root privileges, potentially taking full control of the router, intercepting network traffic, or using it as a pivot point into internal networks.
Likely Case
Attackers would gain remote code execution on vulnerable routers, enabling them to modify router settings, intercept traffic, or deploy malware to connected devices.
If Mitigated
With proper network segmentation and firewall rules limiting access to router management interfaces, exploitation attempts would be blocked before reaching vulnerable systems.
🎯 Exploit Status
The exploit has been made public and appears to be straightforward to implement based on the vulnerability details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.tenda.com.cn/
Restart Required: Yes
Instructions:
1. Check Tenda's official website for firmware updates. 2. Download the latest firmware for RX3 routers. 3. Access router admin interface. 4. Navigate to firmware upgrade section. 5. Upload and apply the new firmware. 6. Reboot the router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router management interface
Network Segmentation
allIsolate router management interface to trusted networks only
🧯 If You Can't Patch
- Replace affected routers with models from different vendors
- Implement strict firewall rules to block all external access to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via admin interface. If version is 16.03.13.11, the device is vulnerable.Check Version:
Login to router admin interface and check System Status or Firmware Information pageVerify Fix Applied:
After updating firmware, verify the version number has changed from 16.03.13.11 to a newer version.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /goform/formSetQosBand
- Multiple failed authentication attempts to router interface
- Unexpected router configuration changes
Network Indicators:
- Unusual traffic patterns to router management ports (typically 80/443)
- Suspicious payloads in HTTP requests to router
SIEM Query:
source="router_logs" AND (uri="/goform/formSetQosBand" OR method="POST" AND uri CONTAINS "formSetQosBand")