The vulnerability identified as CVE-2025-11586 affects the Tenda AC7 router firmware version 15.03.06.44. It is a stack-based buffer overflow triggered by manipulating the 'newVersion' parameter in the /goform/setNotUpgrade endpoint. This endpoint is part of the router's web management interface, which is accessible remotely over the network. The flaw allows an attacker to send a specially crafted request that overflows the stack buffer, potentially overwriting the return address or other control data, leading to arbitrary code execution. The vulnerability does not require user interaction or prior authentication, making it highly exploitable remotely. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (C:H, I:H, A:H). Although no known exploits are currently active in the wild, the public disclosure of exploit code increases the risk of imminent exploitation. The absence of an official patch at the time of disclosure necessitates interim mitigations. The vulnerability could be leveraged to compromise network infrastructure, intercept or manipulate traffic, or pivot into internal networks, posing a significant threat to organizations relying on Tenda AC7 devices.

For European organizations, exploitation of CVE-2025-11586 could lead to full compromise of affected Tenda AC7 routers, resulting in unauthorized access to internal networks, interception of sensitive data, and disruption of network services. Given the router's role as a gateway device, attackers could establish persistent footholds, launch further attacks against internal systems, or exfiltrate confidential information. This is particularly critical for enterprises, government agencies, and critical infrastructure operators that depend on secure and reliable network connectivity. The high severity and remote exploitability mean that even organizations with limited security monitoring could be compromised. The impact extends to potential regulatory and compliance violations under GDPR if personal data confidentiality is breached. Additionally, disruption of availability could affect business continuity and operational processes.

Immediate mitigation steps include isolating Tenda AC7 devices from untrusted networks and restricting access to the router's management interface to trusted IP addresses only. Network administrators should implement firewall rules to block inbound traffic targeting the /goform/setNotUpgrade endpoint or the router's web management ports from external sources. Monitoring network traffic for anomalous requests to the vulnerable endpoint can help detect exploitation attempts. Organizations should engage with Tenda for firmware updates or patches addressing this vulnerability and apply them promptly once available. In the interim, consider replacing vulnerable devices with alternative hardware if feasible. Employ network segmentation to limit the impact of compromised devices and enforce strong network access controls. Regularly audit router configurations to ensure no unnecessary services or remote management features are enabled. Finally, maintain updated intrusion detection/prevention systems with signatures for this vulnerability once released.