CVE-2026-5355 Trendnet TEW-657BRM setup.cgi vpn_drop os command injection

Medium 5.3 Published 2 Apr 2026 Updated 2 Apr 2026

Remote attackers can execute arbitrary OS commands via the vpn_drop function in the discontinued Trendnet TEW-657BRM router.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-5355?

CVE-2026-5355 is a medium-severity command injection vulnerability in Trendnet TEW-657BRM, published on 2 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability has been found in Trendnet TEW-657BRM 1.00.1. Affected by this issue is the function vpn_drop of the file /setup.cgi. The manipulation of the argument policy_name leads to os command injection. The attack is possible to be carried out remotely. The exploit has been disclosed to the public and may be used. The vendor confirms, that "[t]he product in question (...) has been discontinued and end of life since June 23, 2011, that is more than 14 years ago. We no longer provide support for this product, so we are not able to confirm the vulnerabilities. We will make an announcement on our website's product support page and notify customers who registered their products with us." This vulnerability only affects products that are no longer supported by the maintainer.

Weakness: CWE-78, CWE-77

Which versions are affected by CVE-2026-5355?

It affects 1 product.

Products include Trendnet Tew-657brm Firmware.

How do I fix CVE-2026-5355?

No fix has been published for CVE-2026-5355 yet. Limit exposure of the affected software until one is available.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2026-5355 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5355 exists.

Sources

Also known as GHSA-64fp-48cj-ffvx.