CVE-2026-3400 in AC15
Summary
by MITRE • 03/02/2026
A security flaw has been discovered in Tenda AC15 up to 15.13.07.13. Affected by this issue is some unknown functionality of the file /goform/TextEditingConversion. The manipulation of the argument wpapsk_crypto2_4g results in stack-based buffer overflow. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks.
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Analysis
by VulDB Data Team • 03/03/2026
The vulnerability identified as CVE-2026-3400 represents a critical stack-based buffer overflow flaw in the Tenda AC15 wireless router firmware version 15.13.07.13 and earlier. This vulnerability specifically affects the /goform/TextEditingConversion endpoint within the device's web interface, which serves as a communication channel between the user and the router's underlying system. The flaw manifests when processing the wpapsk_crypto2_4g argument, which is typically used in wireless network configuration parameters. The buffer overflow occurs due to insufficient input validation and bounds checking within the firmware's handling of this particular parameter, creating a potential execution path for malicious actors to manipulate the device's memory structure.
The technical exploitation of this vulnerability leverages the stack-based buffer overflow condition where an attacker can overwrite adjacent memory locations in the router's execution stack. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a high-severity issue in the Common Weakness Enumeration catalog. The attack vector is remote, meaning that an unauthenticated attacker can potentially exploit this vulnerability without requiring physical access to the device. The fact that a public exploit has been released significantly increases the risk profile, as it eliminates the need for advanced exploitation techniques and makes the vulnerability accessible to a broader range of threat actors.
The operational impact of this vulnerability extends beyond simple denial of service or data corruption scenarios. Successful exploitation could potentially allow attackers to execute arbitrary code on the affected router, leading to complete compromise of the device. This compromise would enable attackers to gain unauthorized access to the network, potentially allowing them to monitor traffic, redirect requests, or establish persistent access points. The implications are particularly severe for home and small office networks where routers often serve as the primary gateway to the internet and may not have robust security monitoring in place. The vulnerability affects the wireless configuration functionality of the device, which means that an attacker could potentially modify wireless security settings, weaken encryption, or even disable security features entirely.
Mitigation strategies for this vulnerability should include immediate firmware updates from Tenda, as the vendor should release patches addressing the buffer overflow condition in the TextEditingConversion endpoint. Network administrators should also implement network segmentation and monitoring to detect unusual traffic patterns that might indicate exploitation attempts. The implementation of web application firewalls and intrusion detection systems can help identify and block malicious requests targeting the vulnerable /goform/TextEditingConversion endpoint. Additionally, organizations should consider disabling unnecessary web management interfaces when possible, and ensure that wireless network credentials are properly secured and regularly rotated. This vulnerability aligns with ATT&CK technique T1071.004 Application Layer Protocol: DNS, as attackers might use the compromised device as a pivot point for further network reconnaissance and lateral movement activities. The presence of a public exploit means that organizations should prioritize remediation efforts, as the window for exploitation is likely to be extended by the availability of readily accessible attack tools.