CVE-2026-77004 Comfast CF-N1-S mbox-config sprintf command injection

Medium 5.3 Published 20 Aug 2026 Updated 20 Aug 2026

Remote attackers can execute arbitrary commands on Comfast CF-N1-S routers via a command injection vulnerability in the mbox-config CGI script.

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-2026-77004?

CVE-2026-77004 is a medium-severity command injection vulnerability in Comfast CF-N1-S, published on 20 Aug 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 Comfast CF-N1-S 2.6.0.1. This impacts the function sprintf of the file /cgi-bin/mbox-config?method=SET&section=ptest_sn. Executing a manipulation of the argument sn can lead to command injection. The attack can be launched remotely. The exploit has been published and may be used.

Weakness: CWE-77, CWE-74

Which versions are affected by CVE-2026-77004?

How do I fix CVE-2026-77004?

No fix has been published for CVE-2026-77004 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-2026-77004 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77004 exists.

Sources

Also known as GHSA-m27q-v5c6-r932.