CVE-2026-19822 in W20E
Summary
by MITRE • 08/14/2026
A vulnerability was identified in Tenda W20E 15.11.0.6(1068_1546_841)_CN_TDC. This issue affects the function lstAdd of the file /goform/editQos of the component QoS Edit. Such manipulation of the argument qosListConnecttedNum leads to stack-based buffer overflow. The attack may be launched remotely. The exploit is publicly available and might be used.
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Analysis
by VulDB Data Team • 08/14/2026
This vulnerability resides within the Tenda W20E router firmware version 15.11.0.6(1068_1546_841)_CN_TDC, specifically targeting the Quality of Service editing component. The flaw manifests in the lstAdd function located within the /goform/editQos file, representing a critical security weakness that enables remote code execution through a stack-based buffer overflow exploit. The vulnerability stems from improper input validation when processing the qosListConnecttedNum argument, which allows attackers to manipulate memory layout and potentially overwrite adjacent stack variables. This particular implementation flaw creates an opportunity for adversaries to execute arbitrary code on the affected device with elevated privileges.
The technical nature of this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, where insufficient bounds checking permits data to overflow into adjacent memory locations. The attack vector is remotely accessible through the web interface, making it particularly dangerous as no physical access or local network presence is required for exploitation. According to ATT&CK framework, this represents a privilege escalation technique under T1068, where an attacker leverages a software vulnerability to gain higher privileges on the target system. The public availability of exploit code significantly increases the risk profile, as it eliminates the need for advanced technical skills or custom development to compromise affected devices.
The operational impact of this vulnerability extends beyond simple remote code execution, potentially enabling complete system compromise and persistent access to the network infrastructure. An attacker could gain full control over the router's operations, including but not limited to modifying network configurations, redirecting traffic, creating backdoors, or using the device as a pivot point for further attacks within the local network. The QoS component specifically controls bandwidth allocation and traffic management, making this vulnerability particularly dangerous as it could be used to disrupt network services or establish covert communication channels. Organizations relying on Tenda W20E routers for network infrastructure may face severe security implications including data exfiltration, man-in-the-middle attacks, or complete network compromise.
Mitigation strategies should prioritize immediate firmware updates from Tenda if available, though given the public exploit availability, organizations must implement additional protective measures. Network segmentation and firewall rules should be configured to restrict access to router management interfaces, while monitoring systems should be deployed to detect anomalous traffic patterns that might indicate exploitation attempts. Security teams should also consider implementing intrusion detection systems specifically trained to recognize patterns associated with buffer overflow exploits targeting embedded devices. The vulnerability highlights the importance of secure coding practices in network infrastructure devices and underscores the necessity for regular security assessments of third-party firmware components. According to NIST guidelines, organizations should maintain inventory of all networked devices and ensure timely patch management processes are in place to address known vulnerabilities before they can be exploited by malicious actors.