Medium severity · published Oct 7, 2026
CVE-2026-20173
Cisco NX-OS Software Denial of Service Vulnerability
5.8
CVSS
0.4%
EPSS
No
On KEV
Description
A vulnerability in Cisco NX-OS Software could allow an unauthenticated, remote attacker to exhaust system resources, causing a denial of service (DoS) condition.
This vulnerability exists because rate limiting was improperly applied to some protocols. An attacker could exploit this vulnerability by sending a high rate of UDP or TCP connections to a data plane interface on an affected device. A successful exploit could allow the attacker to cause instability to various routing and control plane protocols through some packet loss and temporary disruptions, causing a DoS condition. This DoS condition will clear without manual intervention soon after the high rate of traffic is stopped.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CN
Cisco NX-OS Software · Cisco
8.2(5); 7.3(5)D1(1); 8.4(2); 8.4(3); 9.2(3); 9.2(2v); +34 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20173
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20173
sec.cloudapps.cisco.com
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-nscpdos-SnderkC7
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