2026-017: Critical Vulnerability in Cisco Secure Email Gateway

On 14 October 2026, Cisco published a security advisory addressing a critical vulnerability affecting the Advanced Malware Protection (AMP) feature of Cisco Secure Email Gateway. This vulnerability could allow an unauthenticated, remote attacker to write arbitrary files and execute commands with root privileges on the underlying operating system. The Cisco PSIRT is aware of active exploitation of this vulnerability. CERT-EU strongly recommends updating the Content Scanner Tools package or upgrading Cisco AsyncOS Software to a fixed release as soon as possible, prioritising appliances reachable from the internet. CERT-EU also recommends checking all affected appliances for indicators of compromise.