Palo Alto Networks Firewall Vulnerability Allows an Attacker to Force Firewalls into a Reboot Loop

Palo Alto Networks disclosed CVE-2026-0229, a critical DoS flaw in the PAN-OS Advanced DNS Security (ADNS) feature that can let unauthenticated attackers crash affected firewalls into continuous reboot/maintenance cycles; impacted PAN-OS releases include 12.1 (<12.1.4) and 11.2 (<11.2.10) when ADNS is enabled with a spyware profile set to block/sinkhole/alert. Cloud NGFW and Prisma Access are unaffected, there are no workarounds or threat prevention signatures to detect exploitation, and Palo Alto recommends immediate upgrades to the patched versions (no known active exploitation reported).