CVE-2026-20124

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.

Scoring

Severity

HIGH

CVSS base score

7.7

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

EPSS probability

0.34%

CWE

CWE-772

Published

2026-08-05

Last modified

2026-08-05

Affected products

• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software
• Cisco Cisco IOS XE Software

Weakness type

• CWE-772

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