CVE-2026-20167 Cisco IoT Field Network Director Remote Device Denial of Service Vulnerability

High 7.7 Published 6 May 2026 Updated 6 May 2026

An authenticated low-privilege attacker can cause a denial of service on remotely managed routers by submitting crafted input to the web 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-2026-20167?

CVE-2026-20167 is a high-severity denial of service vulnerability in Cisco IoT Field Network Director (IoT-FND), published on 6 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability in the web-based management interface of Cisco IoT Field Network Director could allow an authenticated, remote attacker with low privileges to cause a DoS condition on a remotely managed router. This vulnerability is due to improper error handling. An attacker could exploit this vulnerability by submitting crafted input to the web-based management interface. A successful exploit could allow the attacker to request unauthorized files from a remote router, causing the router to reload and resulting in a DoS condition.

Weakness: CWE-284

Which versions are affected by CVE-2026-20167?

It affects 1 product.

Products include Cisco Iot Field Network Director.

How do I fix CVE-2026-20167?

No fix has been published for CVE-2026-20167 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-20167 being exploited?

There is no known exploitation of CVE-2026-20167 in the wild and no public exploit code.

Sources

Also known as GHSA-48h9-c48p-4x99.