CVE-2026-1420 identifies a critical buffer overflow vulnerability in the Tenda AC23 router firmware version 16.03.07.52. The vulnerability resides in an unspecified function associated with the /goform/WifiExtraSet endpoint, specifically triggered by malicious manipulation of the wpapsk_crypto parameter. This buffer overflow can be exploited remotely over the network without requiring authentication or user interaction, which significantly lowers the barrier for attackers. The overflow potentially allows attackers to execute arbitrary code with elevated privileges or cause a denial of service by crashing the device. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges or user interaction needed. Although no active exploitation has been reported, a public exploit is available, increasing the likelihood of future attacks. The vulnerability affects a widely deployed consumer and small business router model, which is often used in home and office environments, potentially exposing sensitive network segments. The lack of an official patch at the time of publication necessitates immediate mitigation through network controls and monitoring. The vulnerability's exploitation could lead to network compromise, data interception, or disruption of critical services.

For European organizations, this vulnerability poses a significant risk, particularly for small and medium enterprises and home office setups relying on Tenda AC23 routers. Successful exploitation could lead to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network availability. Critical infrastructure sectors such as healthcare, finance, and government agencies using these devices could face operational disruptions or data breaches. The remote and unauthenticated nature of the exploit increases the attack surface, especially if management interfaces are exposed to the internet or poorly segmented. Additionally, the availability of a public exploit raises the risk of automated attacks and widespread compromise. Organizations may face regulatory and compliance consequences if breaches occur due to unpatched vulnerabilities. The impact extends beyond direct victims as compromised routers can be leveraged in botnets or as pivot points for lateral movement within networks.

Immediate mitigation should focus on network-level controls: restrict access to router management interfaces by implementing firewall rules to limit connections to trusted IP addresses only. Disable remote management features if not required. Monitor network traffic for unusual activity targeting the /goform/WifiExtraSet endpoint or anomalous wpapsk_crypto parameter usage. Employ intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect exploitation attempts. Organizations should engage with Tenda for firmware updates or advisories and apply patches as soon as they become available. In the interim, consider replacing vulnerable devices with models from vendors with robust security update policies. Conduct regular network segmentation to isolate critical systems from vulnerable devices. Educate users about the risks of exposed routers and encourage secure configuration practices. Maintain comprehensive logging and incident response plans to quickly identify and respond to exploitation attempts.