CVE-2026-20033 HIGH

CVE-2026-20033: Cisco NX-OS Software Denial of Service Vulnerability

Vendor Cisco
Product Cisco NX-OS System Software in ACI Mode
Weakness CWE-805
Published February 25, 2026
Last update February 25, 2026

CVSS base score

7.4/10
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

What the vulnerability does

01Description

A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only the out-of-band (OOB) management interface is affected.

Key dates

02Disclosure timeline

February 25, 2026 CVE published
February 25, 2026 Record updated