CVE-2026-77683 Comfast CF-N1-S mbox-config system command injection

Critical 9.4 Published 21 Aug 2026 Updated 21 Aug 2026

Remote attackers can execute arbitrary system commands on Comfast CF-N1-S routers via the mbox-config interface, requiring immediate attention from network administrators.

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-2026-77683?

CVE-2026-77683 is a critical command injection vulnerability in Comfast CF-N1-S, published on 21 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A security flaw has been discovered in Comfast CF-N1-S 2.6.0.1. Affected by this issue is the function system of the file /cgi-bin/mbox-config?method=SET&section=ntp_timezone. The manipulation of the argument timestr results in command injection. The attack can be launched remotely. The exploit has been released to the public and may be used for attacks.

Weakness: CWE-77, CWE-74

Which versions are affected by CVE-2026-77683?

How do I fix CVE-2026-77683?

No fix has been published for CVE-2026-77683 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-2026-77683 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77683 exists.

Sources

Also known as GHSA-hh37-xhg2-x62w.