High Vulnerability in Cisco IOS and IOS XE Software (CERT-EU Security Advisory 2025-035) On September 24, 2025, Cisco released a security advisory regarding a high severity vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software. The vulnerability is being exploited in the wild. It is recommended updating as soon as possible and conduct a compromise assessment on devices that are exposing SNMP on the Internet. It is also recommended not allowing access to SNMP over untrusted network (i.e. on the Internet). https://www.cert.europa.eu/publications/security-advisories/2025-035/