CVE-2026-4976 Totolink LR350 cstecgi.cgi setWiFiGuestCfg buffer overflow

High 8.7 Published 27 Mar 2026 Updated 30 Mar 2026

Remote attackers can trigger a buffer overflow in the Totolink LR350 router's guest WiFi configuration handler, potentially leading to code execution or service disruption.

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-2026-4976?

CVE-2026-4976 is a high-severity memory corruption vulnerability in Totolink LR350, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability was found in Totolink LR350 9.3.5u.6369_B20220309. This vulnerability affects the function setWiFiGuestCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ssid results in buffer overflow. The attack can be launched remotely. The exploit has been made public and could be used.

Weakness: CWE-120, CWE-119

Which versions are affected by CVE-2026-4976?

It affects 1 product.

Products include Totolink Lr350 Firmware.

How do I fix CVE-2026-4976?

No fix has been published for CVE-2026-4976 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-2026-4976 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4976 exists.

Sources

Also known as GHSA-h682-387f-gvmv.