High severity · published Feb 25, 2026
CVE-2026-20010
Cisco Nexus 3000 and 9000 Series Switches Link Layer Discovery Protocol Denial of Service Vulnerability
7.4
CVSS
0.2%
EPSS
No
On KEV
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).
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CN
Cisco NX-OS Software · Cisco
10.3(1); 10.3(2); 10.3(3); 10.4(1); 10.3(99w); 10.3(3w); +11 more · source: vendor
CN
Cisco NX-OS System Software in ACI Mode · Cisco
16.0(2h); 16.0(2j); 16.0(3d); 16.0(3e); 16.0(4c); 16.0(5h); +15 more · source: vendor
CU
Cisco Unified Computing System (Managed) · Cisco
4.3(4e); 4.3(6b); 4.3(4c); 4.3(4f); 4.3(6d); 4.3(5e); +7 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20010
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20010
sec.cloudapps.cisco.com
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n3kn9k_aci_lldp_dos-NdgRrrA3
More from Cisco NX-OS Software
6.7
CVE-2024-20399
Cisco NX-OS Software CLI Command Injection Vulnerability
9.8
CVE-2026-76501
Cisco Nexus 9000 Series Switches SRv6 OAM (NGOAM) Remote Code Execution Vulnerability
9.8
CVE-2026-76486
Cisco Nexus 3000 and 9000 Series Switches VXLAN OAM (NGOAM) Remote Code Execution Vulnerability
9.8
CVE-2026-76485
Cisco Nexus 3000 and 9000 Series Switches VXLAN OAM (NGOAM) Remote Code Execution Vulnerability
9.8
CVE-2026-76459
Cisco NX-OS Software Security Hardening Release: October 2026 - Out-of-bounds Write Vulnerabilities
