Actively exploited in the wild

Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability

Cisco - IOS and IOS XE · Listed in the CISA KEV since 2025-09-29. This indicates confirmed attacks in production environments.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

CVE-2025-20352

HighCVSS 7.7KEV

Published: 24/09/2025(UTC)Updated: 17/06/2026(UTC)Translated: 18/09/2026(UTC)NVD NIST

Summary

A vulnerability in the SNMP subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition, and an authenticated, remote attacker with high privileges to execute code as the root user. The vulnerability is due to a stack overflow condition in the SNMP subsystem and affects all versions of SNMP.

Risk Assessment

An attacker with access to an SNMP community string or SNMPv3 credentials can remotely crash the device or — with high privileges — gain full control of the system. The risk is high for Cisco network devices with SNMP enabled.

Recommendation

Install Cisco patches for IOS and IOS XE as soon as possible. Also restrict SNMP access, change default community strings, and disable SNMP where it is not required.

Other vulnerabilities in Cisco IOS and Cisco IOS XE Software

CVE-2016-9201High
A vulnerability in the Zone-Based Firewall feature of Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to pass traffic that should otherwise have been dropped based on the configuration.

Original NVD description (English source)

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials. An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks. This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system. Note: This vulnerability affects all versions of SNMP.