PT-2026-21947 · Cisco · Cisco Nexus 9000 Series Fabric Switches

Published 2026-02-25 · Updated 2026-02-27 · CVE-2026-20033

Positive Technologies (AI Summary)

CVSS v3.1

7.4

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Cisco Nexus 9000 Series Fabric Switches versions (affected versions not specified)

Description A flaw exists in Cisco Nexus 9000 Series Fabric Switches operating in ACI mode that may allow a remote, unauthenticated attacker to disrupt service. The issue stems from inadequate validation of certain Ethernet frames. An attacker could leverage this by transmitting a specially crafted Ethernet frame to the management interface of a vulnerable device, potentially causing an unexpected reload and resulting in a denial of service (DoS) condition. Only the out-of-band (OOB) management interface is impacted.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

Weakness Enumeration

CWE-805

Related Identifiers

CVE-2026-20033

Affected Products

Cisco Nexus 9000 Series Fabric Switches

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2026-20033 · Security Note
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-cpdos-qLsv6pFD · Vendor Advisory
• https://twitter.com/infoflowcloud/status/2027100403708334371 · Twitter Post
• https://twitter.com/CVEnew/status/2027099318998688144 · Twitter Post
• https://twitter.com/VulmonFeeds/status/2026798922438476143 · Twitter Post
• https://t.me/cveNotify/153487 · Telegram Post