A denial-of-service (DoS) vulnerability in Palo Alto Networks PAN-OS software enables an unauthenticated attacker to reboot a firewall by sending a specially crafted packet through the dataplane. Repeated attempts to initiate a reboot causes the firewall to enter maintenance mode. This issue is applicable to the PAN-OS software versions listed below on PA-Series firewalls, VM-Series firewalls, and Prisma® Access software. This issue does not affect Cloud NGFW. ​​We have successfully completed the Prisma Access upgrade for all customers, with the exception of those facing issues such as conflicting maintenance windows. Remaining customers will be promptly scheduled for an upgrade through our standard upgrade process.