CVE-2026-1143 TOTOLINK A3700R cstecgi.cgi setWiFiEasyGuestCfg buffer overflow

High 8.7 Published 19 Jan 2026 Updated 23 Feb 2026

Remote attackers can trigger a buffer overflow in the TOTOLINK A3700R router via the setWiFiEasyGuestCfg function, 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-2026-1143?

CVE-2026-1143 is a high-severity memory corruption vulnerability in TOTOLINK A3700R, published on 19 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A weakness has been identified in TOTOLINK A3700R 9.1.2u.5822_B20200513. This affects the function setWiFiEasyGuestCfg of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument ssid can lead to buffer overflow. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks.

Weakness: CWE-120, CWE-119

Which versions are affected by CVE-2026-1143?

It affects 1 product.

Products include Totolink A3700r Firmware.

How do I fix CVE-2026-1143?

No fix has been published for CVE-2026-1143 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-2026-1143 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-1143 exists.

Sources

Also known as GHSA-m237-23r2-f38w.