CVE-2026-20124

HIGH · CVSS 7.7 · EPSS 0.35% · CWE CWE-772

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.

CVE-2026-20124 is confirmed by Cisco as affecting 2 products, including Cisco IOS XE Software and Cisco IOS XE Catalyst SD-WAN, via 1 advisory (CVSS 7.7; EPSS 0.3%).

2 products with CSAF evidence