Critical PAN-OS Vulnerability Demands Immediate Attention

A joint advisory warns of CVE-2026-0300, a critical (CVSS 9.3) out-of-bounds buffer overflow in Palo Alto PA-Series and VM-Series firewalls' USER-ID authentication portal that can yield unauthenticated root access. Affected PAN-OS versions include 10.2, 11.1, 11.2, and 12.1; limited exploitation has been observed across education, healthcare, and ISP sectors and patches are not expected until May 13, so organizations should monitor ports 6080–6082 for oversized HTTP POSTs to /php/uid.php, isolate inbound traffic, apply allow lists, watch for suspicious outbound connections, and update Threat Prevention signatures and community detection rules.