CVE-2026-20010

Cisco Nexus 3000 and 9000 Series Switches Link Layer Discovery Protocol Denial of Service Vulnerability

Severity
High 7.4
CVSS 3.1
Exploited
Not listed
EPSS
0.002
6.3th percentile
Discovered by
Third party
Published by the vendor
Published
Feb 25, 2026
Assigned by cisco

Description

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature of Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause the LLDP process to restart, which could cause an affected device to reload unexpectedly. This vulnerability is due to improper handling of specific fields in an LLDP frame. An attacker could exploit this vulnerability by sending a crafted LLDP packet to an interface of an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition. Note: LLDP is a Layer 2 link protocol. To exploit this vulnerability, an attacker would need to be directly connected to an interface of an affected device, either physically or logically (for example, through a Layer 2 Tunnel configured to transport the LLDP protocol).

Weakness: CWE-805

Affected products

Vendor Product Category Matched by
Cisco Cisco NX-OS Software Routing & Switching cna-assigner
Cisco Cisco Unified Computing System (UCS) Other Products cna-assigner
Vendor-reported affected versions (3)
  • Cisco · Cisco NX-OS Software
  • Cisco · Cisco NX-OS System Software in ACI Mode
  • Cisco · Cisco Unified Computing System (Managed)