SNMP-based monitoring is unreliable on modern high-speed networks due to fundamental 32-bit counter limits causing misleading metrics and noisy alerts.
As many as 2 million Cisco devices affected by actively exploited 0-day
Up to two million Cisco IOS and IOS XE devices are vulnerable to CVE-2025-20352, an SNMP stack overflow allowing remote DoS or root-level code execution.
Cisco Patches Zero-Day Flaw Affecting Routers and Switches
A critical SNMP stack overflow (CVE-2025-20352) in IOS/IOS XE is being exploited; apply Cisco patches immediately to prevent DoS or remote root code execution.