CVE-2026-5349 Trendnet TEW-657BRM setup.cgi add_apcdb stack-based overflow

High 8.7 Published 2 Apr 2026 Updated 2 Apr 2026

Remote attackers can execute arbitrary code via a stack-based buffer overflow in the setup.cgi script of discontinued Trendnet routers.

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-2026-5349?

CVE-2026-5349 is a high-severity memory corruption 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 was identified in Trendnet TEW-657BRM 1.00.1. The affected element is the function add_apcdb of the file /setup.cgi. The manipulation of the argument mac_pc_dba leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit is publicly available and might 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-121, CWE-119

Which versions are affected by CVE-2026-5349?

It affects 1 product.

Products include Trendnet Tew-657brm Firmware.

How do I fix CVE-2026-5349?

No fix has been published for CVE-2026-5349 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-5349 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5349 exists.

Sources

Also known as GHSA-896m-qf6h-hqqq.