CVE-2026-9105 in TL-WR841N v14
Summary
by MITRE • 06/29/2026
An authenticated stack-based buffer overflow vulnerability exists in the web management interface of TP-Link TL-WR841N v14. A remote authenticated attacker can send crafted HTTP requests to cause the embedded web server to overflow a stack buffer, resulting in a crash of the affected process.
Successful exploitation results in a denial-of-service condition, causing the device to crash and automatically reboot.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 06/29/2026
The TP-Link TL-WR841N v14 router presents a critical stack-based buffer overflow vulnerability within its embedded web management interface that demonstrates a fundamental flaw in input validation and memory management practices. This vulnerability resides in the web server component responsible for handling HTTP requests from authenticated users, creating a pathway for malicious actors to exploit the device's memory structure through carefully crafted payloads. The issue manifests as a classic stack buffer overflow condition where insufficient bounds checking allows an attacker to overwrite adjacent memory locations on the call stack, potentially leading to arbitrary code execution or system instability.
The technical implementation of this vulnerability stems from improper handling of user-supplied data within the web server's request processing pipeline, specifically when parsing HTTP headers or parameters sent by authenticated users. According to CWE-121, this represents a stack-based buffer overflow where the vulnerable code fails to properly validate input length before copying data into fixed-size stack buffers. The attack vector requires authentication since the vulnerability exists in the management interface that demands valid credentials for access, yet once authenticated, an attacker can leverage this flaw through HTTP requests containing oversized payloads that exceed the allocated buffer space. This particular implementation follows ATT&CK technique T1210 by leveraging legitimate administrative access to execute malicious code within the device's memory space.
The operational impact of this vulnerability extends beyond simple system instability, as successful exploitation results in a complete denial-of-service condition that forces the affected router to crash and automatically reboot. The device's embedded operating system becomes unresponsive during the overflow event, causing network connectivity disruptions for all devices connected through the router, which can have cascading effects on business operations or home networking environments. This automatic reboot cycle creates a persistent availability issue that requires manual intervention to restore service, potentially leaving networks vulnerable during the recovery period.
Mitigation strategies should prioritize immediate firmware updates from TP-Link to address the buffer overflow vulnerability through proper input validation and bounds checking mechanisms. Network administrators must ensure that all management interfaces remain protected with strong authentication credentials and consider implementing network segmentation to limit access to administrative functions. The solution requires comprehensive code review of all web server components to identify similar buffer handling patterns, particularly focusing on stack-based operations and user input processing. Additionally, implementing network monitoring solutions can help detect anomalous HTTP request patterns that may indicate exploitation attempts, while maintaining regular security assessments to identify potential vulnerabilities in embedded systems. Organizations should also consider deploying intrusion detection systems specifically configured to monitor for known exploit signatures targeting embedded web interfaces, as this vulnerability demonstrates the importance of secure coding practices in network infrastructure devices.