CVE-2025-57086 is a high-severity vulnerability affecting the Tenda W30E router running firmware version V16.01.0.19 (build 5037). The vulnerability is a stack-based buffer overflow occurring in the formDeleteMeshNode function when processing a specifically crafted string parameter. This flaw allows an unauthenticated remote attacker to send a malicious request that triggers the overflow, leading to a Denial of Service (DoS) condition by crashing or destabilizing the device. The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow), indicating that improper bounds checking on input data leads to memory corruption. The CVSS v3.1 base score is 7.5, reflecting a high impact primarily on availability, with no confidentiality or integrity impact. The attack vector is network-based (AV:N), requiring no privileges (PR:N) or user interaction (UI:N), making exploitation relatively straightforward for attackers with network access to the device. Currently, there are no known exploits in the wild, and no patches have been published yet. The vulnerability's presence in a consumer-grade mesh Wi-Fi router suggests potential exposure in home and small office environments where these devices are deployed. Given the nature of the vulnerability, exploitation would result in service disruption, potentially impacting network connectivity for affected users.

For European organizations, the impact of CVE-2025-57086 can vary depending on the deployment of Tenda W30E routers within their network infrastructure. While primarily consumer-focused, some small businesses or branch offices might use these devices for mesh networking. Exploitation could lead to denial of service, causing network outages and loss of connectivity, which can disrupt business operations, remote work, and communications. In critical environments relying on continuous network availability, such as healthcare clinics or small financial offices, this could lead to operational delays or data access issues. Although the vulnerability does not compromise confidentiality or integrity, the availability impact alone can have significant operational and reputational consequences. Additionally, the lack of authentication and user interaction requirements increases the risk of remote exploitation by attackers scanning for vulnerable devices. European organizations with remote or unmanaged network segments using Tenda W30E devices are particularly at risk. The absence of a patch at the time of disclosure further elevates the urgency for mitigation.

Given the absence of an official patch, European organizations should implement immediate compensating controls. First, identify and inventory all Tenda W30E devices within the network, especially those exposed to untrusted networks or the internet. Restrict network access to the device management interfaces and mesh networking functions by implementing firewall rules or network segmentation to limit exposure to trusted hosts only. Disable remote management and mesh node deletion features if not required. Monitor network traffic for unusual or malformed requests targeting the formDeleteMeshNode function or related endpoints. Employ intrusion detection/prevention systems (IDS/IPS) with custom signatures to detect attempts to exploit this stack overflow. Plan for firmware updates from Tenda as soon as they become available and prioritize their deployment. For critical environments, consider replacing vulnerable devices with alternative hardware until a secure firmware version is released. Additionally, educate IT staff about this vulnerability and ensure incident response plans include steps for potential DoS events caused by this flaw.