Cisco IoT Field Network Director up to 4.12.1 Web-based Management Interface denial of service

Summaryinfo

A vulnerability classified as critical has been found in Cisco IoT Field Network Director. This issue affects some unknown processing of the component Web-based Management Interface. Performing a manipulation results in denial of service. This vulnerability was named CVE-2026-20167. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco IoT Field Network Director. It has been classified as critical. This affects some unknown processing of the component Web-based Management Interface. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

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.

It is possible to read the advisory at sec.cloudapps.cisco.com. This vulnerability is uniquely identified as CVE-2026-20167 since 10/08/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/06/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

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Productinfo

Vendor

• Cisco

Name

• IoT Field Network Director

Version

• 4.1.0
• 4.1.1
• 4.1.2
• 4.1.3
• 4.2.0
• 4.3.0
• 4.3.1
• 4.3.2
• 4.4.0
• 4.4.1
• 4.4.2
• 4.4.3
• 4.4.4
• 4.5.0
• 4.5.1
• 4.6.0
• 4.6.1
• 4.6.2
• 4.7.0
• 4.7.1
• 4.7.2
• 4.8.0
• 4.8.1
• 4.9.0
• 4.9.1
• 4.9.2
• 4.10.0
• 4.11.0
• 4.12.0
• 4.12.1

License

• commercial

Website

• Vendor: https://www.cisco.com/

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