The vulnerability identified as CVE-2026-24435 affects Shenzhen Tenda Technology Co., Ltd.'s W30E V2 router firmware versions up to V16.01.0.19(5037). It is caused by an insecure Cross-Origin Resource Sharing (CORS) policy implemented on authenticated administrative endpoints. Specifically, the device sets the HTTP header Access-Control-Allow-Origin to '*', which allows any origin to access resources, combined with Access-Control-Allow-Credentials set to true, which permits browsers to include user credentials such as cookies or HTTP authentication information in cross-origin requests. This combination violates CORS security best practices because it enables attacker-controlled websites to perform credentialed cross-origin requests to the router's administrative interface. An attacker can exploit this by tricking an authenticated user into visiting a malicious website, which then issues requests to the router with the user's credentials, potentially executing administrative commands without the user's knowledge. The vulnerability does not require prior authentication or privileges but does require user interaction (visiting a malicious site). The CVSS v4.0 score is 7.1 (high), reflecting network attack vector, low attack complexity, no privileges required, user interaction required, and high impact on confidentiality. No known exploits have been reported in the wild yet. The vulnerability falls under CWE-942 (Permissive Cross-domain Policy with Untrusted Domains), indicating a common web security misconfiguration. This flaw can lead to unauthorized access to router administrative functions, potentially allowing attackers to change configurations, disrupt network services, or exfiltrate sensitive information.

For European organizations, this vulnerability poses a significant risk to network security and operational integrity. Compromise of the Tenda W30E V2 routers could allow attackers to alter network configurations, redirect traffic, disable security controls, or gain deeper access into internal networks. This could lead to data breaches, service disruptions, or facilitate lateral movement by threat actors. Since the vulnerability exploits a web security misconfiguration on administrative endpoints, it directly threatens the confidentiality and integrity of device management. Organizations relying on these routers for critical connectivity or perimeter defense could face increased exposure to cyberattacks. The requirement for user interaction means phishing or social engineering campaigns could be used to trigger exploitation. Given the widespread use of Tenda devices in small to medium enterprises and home office environments across Europe, the vulnerability could affect a broad range of targets, including corporate networks, remote workers, and possibly critical infrastructure segments that utilize these routers. The absence of known exploits in the wild provides a window for proactive mitigation before active attacks emerge.

1. Monitor Shenzhen Tenda's official channels for firmware updates addressing this vulnerability and apply patches promptly once available. 2. In the interim, restrict access to the router's administrative interface to trusted internal networks only, avoiding exposure to the internet or untrusted zones. 3. Implement network segmentation to isolate vulnerable devices from sensitive systems and limit potential lateral movement. 4. Disable remote management features if not required, reducing the attack surface. 5. Employ web filtering and endpoint security solutions to block access to known malicious sites that could host exploit code. 6. Educate users about the risks of visiting untrusted websites while connected to corporate networks to reduce the likelihood of user interaction exploitation. 7. Where possible, configure custom CORS policies or deploy web application firewalls (WAFs) that can detect and block suspicious cross-origin requests targeting administrative endpoints. 8. Regularly audit router configurations and logs for unusual administrative activities that could indicate exploitation attempts. 9. Consider replacing affected devices with more secure alternatives if patching is not feasible or timely.