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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

No data.

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Vendors Products
References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nso-dos-7Egqyc cve-icon cve-icon
History

Wed, 06 May 2026 16:45:00 +0000

Type Values Removed Values Added
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.
Title Cisco Crosswork Network Controller and Cisco Network Services Orchestrator Connection Exhaustion Denial of Service Vulnerability
Weaknesses CWE-400
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-05-06T17:48:12.690Z

Reserved: 2025-10-08T11:59:15.394Z

Link: CVE-2026-20188

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-06T17:16:21.190

Modified: 2026-05-06T17:16:21.190

Link: CVE-2026-20188

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-06T17:30:08Z