CVE-2026-11523: Tenda W20E Web Management PortalAuth formPortalAuth stack-based overflow
A flaw has been found in Tenda W20E 15.11.0.6. This issue affects the function formPortalAuth of the file /goform/PortalAuth of the component Web Management Interface. Executing a manipulation of the argument gotoUrl can lead to stack-based buffer overflow. The attack can be launched remotely. The exploit has been published and may be used.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Disable remote (WAN) web management or configure the device so the web management interface is accessible only from the LAN or specific trusted IPs.
Tenda W20E Web Management Interface remote_management = disabled / restrict to LAN-only - Compensating control
At the network edge or firewall, restrict access to the router's management ports and web interface to a small set of trusted IP addresses or management network segments.
- Compensating control
Block or inspect requests to the vulnerable endpoint /goform/PortalAuth and filter or sanitize the gotoUrl parameter using a WAF, reverse proxy, or firewall rule to prevent exploitation of the identified stack-based buffer overflow.
- Operational
If devices are exposed or exploitation is suspected, isolate affected devices from networks, preserve logs for forensic analysis, and monitor for requests to /goform/PortalAuth or other signs of compromise until a vendor fix is available.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-11523?
The severity of CVE-2026-11523 is rated high, with a score of 8.8.
How does CVE-2026-11523 affect the Tenda W20E?
CVE-2026-11523 affects the Tenda W20E by allowing a stack-based buffer overflow through manipulation of the gotoUrl argument in the Web Management Interface.
Can CVE-2026-11523 be exploited remotely?
Yes, CVE-2026-11523 can be exploited remotely, allowing attackers to execute arbitrary code.
What vulnerabilities are associated with CVE-2026-11523?
CVE-2026-11523 is associated with a stack-based buffer overflow vulnerability in the Web Management Portal.
How can I mitigate the risks of CVE-2026-11523?
To mitigate CVE-2026-11523, it is recommended to update the Tenda W20E to the latest firmware to address the buffer overflow issue.