CVE-2026-20188
Cisco Crosswork Network Controller and Cisco Network Services Orchestrator Advisory
Description
Following the initial publication of the Security Advisory about a denial of service (DoS) condition in Cisco Crosswork Network Controller and Cisco Network Services Orchestrator (NSO), additional information has been made available to the Cisco Product Security Incident Response Team (PSIRT). Upon further analysis, the Cisco PSIRT has reclassified this issue as a customer-configurable, resource management issue rather than a security vulnerability.
INFO
Published Date :
May 6, 2026, 5:16 p.m.
Last Modified :
May 14, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | NONE | [email protected] |
Solution
- Apply vendor-supplied patches for Cisco CNC and NSO.
- Implement stricter rate-limiting on network connections.
- Monitor connection requests for anomalous patterns.
- Reboot affected systems if unresponsive.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-20188.
| URL | Resource |
|---|---|
| https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nso-dos-7Egqyc |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-20188 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-20188
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-20188 vulnerability anywhere in the article.
-
CybersecurityNews
New Cisco Network Vulnerability Let Remote Attacker Cause DoS Attack
Cisco has issued a critical security advisory regarding a high-severity vulnerability impacting its Crosswork Network Controller (CNC) and Network Services Orchestrator (NSO). Tracked formally as CVE- ... Read more
The following table lists the changes that have been made to the
CVE-2026-20188 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2026
Action Type Old Value New Value Changed 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. Following the initial publication of the Security Advisory about a denial of service (DoS) condition in Cisco Crosswork Network Controller and Cisco Network Services Orchestrator (NSO), additional information has been made available to the Cisco Product Security Incident Response Team (PSIRT). Upon further analysis, the Cisco PSIRT has reclassified this issue as a customer-configurable, resource management issue rather than a security vulnerability. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N Removed CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H -
New CVE Received by [email protected]
May. 06, 2026
Action Type Old Value New Value 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-400 Added Reference https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nso-dos-7Egqyc