CVE-2026-4558 Linksys MR9600 SmartConnect.lua smartConnectConfigure os command injection

High 8.7 Published 22 Mar 2026 Updated 23 Mar 2026

Remote attackers can execute arbitrary OS commands on Linksys MR9600 routers via the SmartConnect.lua configuration interface.

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-2026-4558?

CVE-2026-4558 is a high-severity command injection vulnerability in Linksys MR9600, published on 22 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A flaw has been found in Linksys MR9600 2.0.6.206937. Affected is the function smartConnectConfigure of the file SmartConnect.lua. Executing a manipulation of the argument configApSsid/configApPassphrase/srpLogin/srpPassword can lead to os command injection. The attack may be launched remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-78, CWE-77

Which versions are affected by CVE-2026-4558?

It affects 1 product.

Products include Linksys Mr9600 Firmware.

How do I fix CVE-2026-4558?

No fix has been published for CVE-2026-4558 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-2026-4558 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4558 exists.

Sources

Also known as GHSA-c659-rvfg-wgf8.