Cisco Warns of Active Attacks Exploiting Unpatched 0-Day in AsyncOS Email Security Appliances

Cisco has alerted users of a maximum-severity zero-day flaw in Cisco AsyncOS software that has been actively exploited by a China-nexus advanced persistent threat (APT) actor codenamed UAT-9686 in attacks targeting Cisco Secure Email Gateway and Cisco Secure Email and Web Manager. The networking equipment major said it became aware of the intrusion campaign on December 10, 2025, and that it