Cisco has alerted users to 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 has singled out a “limited subset of appliances” with certain ports open to the internet. It’s currently not known how many customers are affected.
“This attack allows the threat actors to execute arbitrary commands with root privileges on the underlying operating system of an affected appliance,” Cisco said in an advisory. “The ongoing investigation has revealed evidence of a persistence mechanism planted by the threat actors to maintain a degree of control over compromised appliances.”









