Critical Buffer Overflow in Palo Alto Networks PAN-OS User-ID Authentication Portal (CVE-2026-0300) (opens in new tab)

OverviewOn May 6, 2026, Palo Alto Networks published a security advisory for CVE-2026-0300, a critical unauthenticated buffer overflow vulnerability affecting PAN-OS PA-Series and VM-Series firewall appliances. Prisma Access, Cloud NGFW, and Panorama appliances are not affected by this vulnerability. The vulnerability carries a CVSSv4 score of 9.3 and has been confirmed as exploited in the wild by the vendor.CVE-2026-0300 is a buffer overflow (CWE-787) in the User-ID™ Authentication Portal (a...