CVE-2026-5851 Totolink A7100RU CGI cstecgi.cgi setUPnPCfg os command injection

Critical 9.3 Published Updated

Remote attackers can execute arbitrary OS commands via the setUPnPCfg function in Totolink A7100RU routers.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-5851?

CVE-2026-5851 is a critical command injection vulnerability in Totolink A7100RU, published on 9 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A security flaw has been discovered in Totolink A7100RU 7.4cu.2313_b20191024. This impacts the function setUPnPCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument enable results in os command injection. The attack can be executed remotely. The exploit has been released to the public and may be used for attacks.

Weakness: CWE-78, CWE-77

Which versions are affected by CVE-2026-5851?

How do I fix CVE-2026-5851?

No fix has been published for CVE-2026-5851 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-2026-5851 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5851 exists.

Sources

Also known as GHSA-323c-322q-9h7v.

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