What happened
A software flaw in Palo Alto Networks next-generation firewalls has been disclosed that can cause devices to enter a continuous reboot loop after processing certain crafted network traffic. According to the report, the issue resides in how specific packet sequences are handled by the firewall’s processing engine, which under particular conditions triggers a system failure that forces the appliance to restart repeatedly. The problem affects multiple models in the Palo Alto Networks next-generation firewall line running particular PAN-OS versions, and administrators reported seeing operational disruptions when the flaw was triggered during normal traffic flows. Palo Alto Networks acknowledged the issue and released updated software builds that correct the packet-handling logic to prevent the reboot behavior from occurring.
Who is affected
Organisations operating affected Palo Alto Networks next-generation firewall models with vulnerable PAN-OS versions are affected, as the flaw can be triggered by network traffic patterns that cause the devices to continuously reboot, impacting security enforcement and connectivity.
Why CISOs should care
A defect in firewall packet processing that results in device reboot loops can undermine perimeter defenses, disrupt network availability, and complicate incident response if core security appliances lose operational stability under real-world traffic.
3 practical actions
Update firewall software. Apply the patched PAN-OS releases that address the packet-handling flaw causing reboot loops.
Validate traffic behavior. Review network traffic patterns for any triggers that may have previously caused instability.
Monitor appliance health. Use logs and telemetry to detect unexpected restarts or operational disruptions on firewall systems.