An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). On all ACX 7000 Series platforms running Junos OS Evolved, and configured with IRBs, if a Customer Edge device (CE) device is dual homed to two Provider Edge devices (PE) a traffic loop will occur when the CE sends multicast packets. This issue can be triggered by IPv4 and IPv6 traffic. This issue affects Junos OS Evolved:  All versions from 22.2R1-EVO and later versions before 22.4R2-EVO, This issue does not affect Junos OS Evolved versions before 22.1R1-EVO.