CVE-2026-20173

Cisco NX-OS Software Denial of Service Vulnerability

Published Oct 7, 2026 CVSS 3.1 · 5.8 Medium EPSS < 1% KEV · Not listed

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.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco NX-OS Software

unknown

Version	Status	Constraints
`8.2(5)`	affected	—
`7.3(5)D1(1)`	affected	—
`8.4(2)`	affected	—
`8.4(3)`	affected	—
`9.2(3)`	affected	—
`9.2(2v)`	affected	—
`7.3(4)D1(1)`	affected	—
`8.2(1)`	affected	—
`9.2(1)`	affected	—
`9.2(2t)`	affected	—
`9.2(3y)`	affected	—
`9.3(2)`	affected	—
`8.1(1)`	affected	—
`8.2(2)`	affected	—
`8.3(2)`	affected	—
`7.3(2)D1(3a)`	affected	—
`9.2(4)`	affected	—
`8.1(2)`	affected	—
`7.3(3)D1(1)`	affected	—
`8.2(3)`	affected	—
`8.4(1)`	affected	—
`7.3(0)DX(1)`	affected	—
`7.3(2)D1(1)`	affected	—
`9.3(1)`	affected	—
`7.3(2)D1(2)`	affected	—
`8.2(4)`	affected	—
`9.3(1z)`	affected	—
`9.2(2)`	affected	—
`8.1(2a)`	affected	—
`7.3(2)D1(3)`	affected	—
`8.3(1)`	affected	—
`7.3(1)D1(1)`	affected	—
`7.3(0)D1(1)`	affected	—
`9.3(3)`	affected	—
`7.3(2)D1(1d)`	affected	—
`9.3(4)`	affected	—
`7.3(6)D1(1)`	affected	—
`8.2(6)`	affected	—
`9.3(5)`	affected	—
`9.3(6)`	affected	—
`8.4(4)`	affected	—
`7.3(7)D1(1)`	affected	—
`9.3(5w)`	affected	—
`8.2(7)`	affected	—
`9.3(7)`	affected	—
`9.3(7k)`	affected	—
`7.3(8)D1(1)`	affected	—
`9.3(7a)`	affected	—
`8.2(7a)`	affected	—
`9.3(8)`	affected	—
`8.4(4a)`	affected	—
`8.4(5)`	affected	—
`8.2(8)`	affected	—
`9.3(9)`	affected	—
`7.3(9)D1(1)`	affected	—
`8.4(6)`	affected	—
`9.3(10)`	affected	—
`8.2(9)`	affected	—
`10.3(1)`	affected	—
`8.4(7)`	affected	—
`10.3(2)`	affected	—
`8.4(6a)`	affected	—
`9.3(11)`	affected	—
`10.3(3)`	affected	—
`8.2(10)`	affected	—
`9.3(12)`	affected	—
`10.4(1)`	affected	—
`8.4(8)`	affected	—
`10.3(99w)`	affected	—
`10.3(3w)`	affected	—
`10.3(99x)`	affected	—
`10.3(3o)`	affected	—
`8.4(9)`	affected	—
`10.3(4)`	affected	—
`10.3(3p)`	affected	—
`10.3(4a)`	affected	—
`10.4(2)`	affected	—
`10.3(3q)`	affected	—
`9.3(13)`	affected	—
`8.2(11)`	affected	—
`10.3(5)`	affected	—
`10.4(3)`	affected	—
`10.3(3x)`	affected	—
`10.3(4g)`	affected	—
`10.5(1)`	affected	—
`8.4(10)`	affected	—
`10.3(3r)`	affected	—
`10.3(6)`	affected	—
`9.3(14)`	affected	—
`10.4(4)`	affected	—
`10.3(4h)`	affected	—
`10.5(2)`	affected	—
`8.4(11)`	affected	—
`10.3(7)`	affected	—
`10.4(5)`	affected	—
`10.5(3)`	affected	—
`9.3(15)`	affected	—
`10.4(4g)`	affected	—
`10.5(4)`	affected	—
`8.4(12)`	affected	—
`10.5(3t)`	affected	—
`10.3(8)`	affected	—
`10.4(6)`	affected	—
`10.5(3s)`	affected	—
`10.5(3e)`	affected	—
`10.5(3o)`	affected	—
`9.3(16)`	affected	—
`10.5(3p)`	affected	—
`10.4(7)`	affected	—
`10.5(5)`	affected	—
`9.3(17)`	affected	—

No data.

Vendor Product Versions

Cisco

Nx-os Software

Version	Status	Scheme	Platform
`8.2(5)`	affected	generic	—
`7.3(5)D1(1)`	affected	generic	—
`8.4(2)`	affected	generic	—
`8.4(3)`	affected	generic	—
`9.2(3)`	affected	generic	—
`9.2(2v)`	affected	generic	—
`7.3(4)D1(1)`	affected	generic	—
`8.2(1)`	affected	generic	—
`9.2(1)`	affected	generic	—
`9.2(2t)`	affected	generic	—
`9.2(3y)`	affected	generic	—
`9.3(2)`	affected	generic	—
`8.1(1)`	affected	generic	—
`8.2(2)`	affected	generic	—
`8.3(2)`	affected	generic	—
`7.3(2)D1(3a)`	affected	generic	—
`9.2(4)`	affected	generic	—
`8.1(2)`	affected	generic	—
`7.3(3)D1(1)`	affected	generic	—
`8.2(3)`	affected	generic	—
`8.4(1)`	affected	generic	—
`7.3(0)DX(1)`	affected	generic	—
`7.3(2)D1(1)`	affected	generic	—
`9.3(1)`	affected	generic	—
`7.3(2)D1(2)`	affected	generic	—
`8.2(4)`	affected	generic	—
`9.3(1z)`	affected	generic	—
`9.2(2)`	affected	generic	—
`8.1(2a)`	affected	generic	—
`7.3(2)D1(3)`	affected	generic	—
`8.3(1)`	affected	generic	—
`7.3(1)D1(1)`	affected	generic	—
`7.3(0)D1(1)`	affected	generic	—
`9.3(3)`	affected	generic	—
`7.3(2)D1(1d)`	affected	generic	—
`9.3(4)`	affected	generic	—
`7.3(6)D1(1)`	affected	generic	—
`8.2(6)`	affected	generic	—
`9.3(5)`	affected	generic	—
`9.3(6)`	affected	generic	—
`8.4(4)`	affected	generic	—
`7.3(7)D1(1)`	affected	generic	—
`9.3(5w)`	affected	generic	—
`8.2(7)`	affected	generic	—
`9.3(7)`	affected	generic	—
`9.3(7k)`	affected	generic	—
`7.3(8)D1(1)`	affected	generic	—
`9.3(7a)`	affected	generic	—
`8.2(7a)`	affected	generic	—
`9.3(8)`	affected	generic	—
`8.4(4a)`	affected	generic	—
`8.4(5)`	affected	generic	—
`8.2(8)`	affected	generic	—
`9.3(9)`	affected	generic	—
`7.3(9)D1(1)`	affected	generic	—
`8.4(6)`	affected	generic	—
`9.3(10)`	affected	generic	—
`8.2(9)`	affected	generic	—
`10.3(1)`	affected	generic	—
`8.4(7)`	affected	generic	—
`10.3(2)`	affected	generic	—
`8.4(6a)`	affected	generic	—
`9.3(11)`	affected	generic	—
`10.3(3)`	affected	generic	—
`8.2(10)`	affected	generic	—
`9.3(12)`	affected	generic	—
`10.4(1)`	affected	generic	—
`8.4(8)`	affected	generic	—
`10.3(99w)`	affected	generic	—
`10.3(3w)`	affected	generic	—
`10.3(99x)`	affected	generic	—
`10.3(3o)`	affected	generic	—
`8.4(9)`	affected	generic	—
`10.3(4)`	affected	generic	—
`10.3(3p)`	affected	generic	—
`10.3(4a)`	affected	generic	—
`10.4(2)`	affected	generic	—
`10.3(3q)`	affected	generic	—
`9.3(13)`	affected	generic	—
`8.2(11)`	affected	generic	—
`10.3(5)`	affected	generic	—
`10.4(3)`	affected	generic	—
`10.3(3x)`	affected	generic	—
`10.3(4g)`	affected	generic	—
`10.5(1)`	affected	generic	—
`8.4(10)`	affected	generic	—
`10.3(3r)`	affected	generic	—
`10.3(6)`	affected	generic	—
`9.3(14)`	affected	generic	—
`10.4(4)`	affected	generic	—
`10.3(4h)`	affected	generic	—
`10.5(2)`	affected	generic	—
`8.4(11)`	affected	generic	—
`10.3(7)`	affected	generic	—
`10.4(5)`	affected	generic	—
`10.5(3)`	affected	generic	—
`9.3(15)`	affected	generic	—
`10.4(4g)`	affected	generic	—
`10.5(4)`	affected	generic	—
`8.4(12)`	affected	generic	—
`10.5(3t)`	affected	generic	—
`10.3(8)`	affected	generic	—
`10.4(6)`	affected	generic	—
`10.5(3s)`	affected	generic	—
`10.5(3e)`	affected	generic	—
`10.5(3o)`	affected	generic	—
`9.3(16)`	affected	generic	—
`10.5(3p)`	affected	generic	—
`10.4(7)`	affected	generic	—
`10.5(5)`	affected	generic	—
`9.3(17)`	affected	generic	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.373% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-nscpdos-SnderkC7

History

Oct 7, 2026 7:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Oct 7, 2026 6:30 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco nx-os Software
Vendors & Products		Cisco Cisco nx-os Software

Oct 7, 2026 4:30 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
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.
Title		Cisco NX-OS Software Denial of Service Vulnerability
Weaknesses		CWE-770
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-nscpdos-SnderkC7
Metrics		cvssV3_1 `{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L'}`