Attack Chain

1. An attacker identifies a Trendnet TEW-635BRM router (firmware up to 1.00.03) accessible remotely.
2. The attacker crafts a malicious HTTP request targeting the router's web interface or a management port.
3. The request includes a specially formed payload that manipulates the ipoa_ipaddr argument within the ipoa_test function.
4. The router's /sbin/rc component processes the request, executing the injected commands embedded within the ipoa_ipaddr argument.
5. The embedded commands are executed on the router with the privileges of the running process, typically root.
6. The attacker achieves remote code execution on the device, gaining complete control over the compromised router.

Impact

Successful exploitation of CVE-2026-15481 grants attackers full remote command execution capabilities on the vulnerable Trendnet TEW-635BRM router. This can lead to unauthorized network access, data interception, denial of service, or the use of the compromised device as a pivot point for further attacks on the internal network. Given that public exploits are available and the product is End-of-Life without any vendor-provided patch, any organization still operating these devices faces an unmitigated, high-risk security exposure. There are no reported victim counts or specific targeted sectors, but any organization using this EOL hardware is at risk.

Recommendation

• Immediately replace any Trendnet TEW-635BRM routers running firmware versions up to 1.00.03, as CVE-2026-15481 affects an End-of-Life product with no available patches.
• Restrict network access to administrative interfaces of all network devices to only trusted internal networks, preventing remote exploitation attempts against CVE-2026-15481.
• Conduct regular audits of network infrastructure to identify and decommission End-of-Life hardware like the Trendnet TEW-635BRM to mitigate unpatchable vulnerabilities.