CVE-2026-20124

Cisco IOS XE Software SNMP Denial of Service Vulnerability

Severity
High 7.7
CVSS 3.1
Exploited
Not listed
EPSS
Discovered by
Third party
Published by the vendor
Published
Aug 5, 2026
Assigned by cisco

Description

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to improper error handling when parsing SNMP requests. This vulnerability affects all versions of SNMP — Versions 1, 2c, and 3. An attacker could exploit this vulnerability by sending a malformed SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly. The attacker must have the SNMPv1 or v2c read-only or read-write community string or valid SNMPv3 user credentials on the affected device.

Weakness: CWE-772

Affected products

Vendor Product Category Matched by
Cisco Cisco IOS XE Software Routing & Switching cna-assigner
Vendor-reported affected versions (1)
  • Cisco · Cisco IOS XE Software