CVE-2026-20048: Cisco NX-OS Software SNMP Denial of Service Vulnerability

DescriptionCVE.org

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper processing when parsing SNMP requests. An attacker could exploit this vulnerability by continuously sending SNMP queries to a specific MIB of an affected device. A successful exploit could allow the attacker to cause a kernel panic on the device, resulting in a reload and a DoS condition. Note: This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMPv1 or SNMPv2c, the attacker must have a valid read-only SNMP community string for the affected system. To exploit this vulnerability through SNMPv3, the attacker must have valid SNMP user credentials for the affected system.

• Cisco · Cisco NX-OS System Software in ACI Mode15.2(1g); 15.2(2e); 15.2(2f); 15.2(2g); 15.2(2h); 15.2(3f) and 51 more

Exploitation

Unlikely (under 1%). EPSS under 1%, or no score yet.

CISA KEV

Not listed

Public check

No public nuclei template

Weakness

Memory Allocation with Excessive Size Value · Denial of Service

Vendor

Cisco

Published

February 2026

Band

Unlikely (under 1%), February 2026

• NVD entrynvd.nist.gov
• CVE recordcve.org
• Weakness CWE-789cwe.mitre.org
• sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvsec.cloudapps.cisco.com