CVE-2025-51088 is a stack-based buffer overflow vulnerability identified in the Tenda AC8V4 router firmware version V16.03.34.06. The vulnerability exists in the /goform/WifiGuestSet endpoint, where improper handling of the 'shareSpeed' argument allows an attacker to overflow the stack buffer. This type of vulnerability typically arises when input data exceeds the allocated buffer size without adequate bounds checking, leading to memory corruption. Exploiting this flaw could enable an attacker to execute arbitrary code with the privileges of the affected process, potentially leading to full compromise of the router device. Since the vulnerability is triggered via manipulation of a web form parameter, it is likely exploitable remotely if the management interface is accessible, especially if exposed to the internet or untrusted networks. No CVSS score has been assigned yet, and no known exploits are currently reported in the wild. However, the nature of stack overflows in network devices makes this a critical security concern, as routers are key infrastructure components that manage network traffic and security policies. The lack of patch links suggests that a fix is not yet publicly available, increasing the urgency for affected users to apply mitigations or monitor for updates.

For European organizations, this vulnerability poses significant risks. Compromise of Tenda AC8V4 routers could lead to interception or manipulation of internal network traffic, unauthorized access to sensitive systems, and potential lateral movement within corporate networks. Given that routers serve as the first line of defense and traffic control, an attacker gaining control could disrupt availability, degrade network performance, or exfiltrate confidential information. Small and medium enterprises (SMEs) and home office setups using this router model are particularly vulnerable due to potentially weaker network segmentation and less rigorous security monitoring. Additionally, critical infrastructure sectors relying on these devices for connectivity could face operational disruptions or espionage risks. The absence of known exploits currently reduces immediate threat but does not eliminate the risk, especially as threat actors often develop exploits rapidly after public disclosure.

Organizations should immediately audit their network environments to identify any Tenda AC8V4 routers running firmware version V16.03.34.06. If found, restrict access to the router's management interface by limiting it to trusted internal IP addresses and disabling remote management over the internet. Network segmentation should be enforced to isolate these devices from critical systems. Employ network intrusion detection systems (NIDS) to monitor for anomalous traffic patterns targeting the /goform/WifiGuestSet endpoint. Until a vendor patch is released, consider replacing vulnerable devices with models from vendors with more robust security track records. Regularly check Tenda's official channels for firmware updates addressing this vulnerability. Additionally, implement strong authentication mechanisms and change default credentials to reduce the risk of unauthorized access. Security teams should prepare incident response plans for potential exploitation scenarios involving router compromise.