CVE-2026-20188
Received Received - Intake
DoS via Inadequate Rate-Limiting in Cisco Crosswork Network Controller and Network Services Orchestrator

Publication date: 2026-05-06

Last updated on: 2026-05-06

Assigner: Cisco Systems, Inc.

Description
A vulnerability in the connection-handling mechanism of Cisco Crosswork Network Controller (CNC) and Cisco Network Services Orchestrator (NSO) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected system. This vulnerability is due to an inadequate implementation of rate-limiting on incoming network connections. An attacker could exploit this vulnerability by sending a large number of connection requests to an affected system. A successful exploit could allow the attacker to exhaust available connection resources, causing Cisco CNC and Cisco NSO to become unresponsive and resulting in a DoS condition for legitimate users and dependent services. A manual reboot of the system is required to recover from this condition.
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Meta Information
Published
2026-05-06
Last Modified
2026-05-06
Generated
2026-05-07
AI Q&A
2026-05-06
EPSS Evaluated
N/A
NVD
EUVD
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
cisco crosswork_network_controller *
cisco network_services_orchestrator *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-400 The product does not properly control the allocation and maintenance of a limited resource.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the connection-handling mechanism of Cisco Crosswork Network Controller (CNC) and Cisco Network Services Orchestrator (NSO). It is caused by an inadequate implementation of rate-limiting on incoming network connections.

An unauthenticated, remote attacker can exploit this by sending a large number of connection requests to the affected system, which can exhaust the system's available connection resources.

As a result, the affected Cisco CNC and Cisco NSO systems become unresponsive, causing a denial of service (DoS) condition that affects legitimate users and dependent services.

Recovery from this condition requires a manual reboot of the system.


How can this vulnerability impact me? :

This vulnerability can impact you by causing a denial of service (DoS) condition on systems running Cisco Crosswork Network Controller (CNC) and Cisco Network Services Orchestrator (NSO).

An attacker can remotely and without authentication exhaust connection resources by flooding the system with connection requests, making the system unresponsive.

This unresponsiveness disrupts legitimate user access and dependent services, potentially causing operational downtime.

Additionally, recovery requires a manual reboot, which may increase system downtime and operational impact.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, you should limit the rate of incoming network connections to the affected Cisco Crosswork Network Controller and Cisco Network Services Orchestrator systems to prevent resource exhaustion.

Since the vulnerability allows an unauthenticated remote attacker to cause a denial of service by exhausting connection resources, monitoring and controlling connection attempts can help reduce the risk.

If a DoS condition occurs, a manual reboot of the affected system is required to recover.


How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:

The vulnerability described causes a denial of service (DoS) condition by exhausting connection resources, but it does not directly impact the confidentiality, integrity, or availability of data in a way that would specifically affect compliance with standards like GDPR or HIPAA.

However, a DoS condition could indirectly affect compliance by disrupting availability requirements mandated by such regulations, since legitimate users and dependent services become unresponsive until a manual reboot is performed.

There is no explicit information provided about direct compliance impacts or data breaches related to this vulnerability.


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