Palo Alto Networks disclosed CVE-2026-0300 on May 9. Unauthenticated buffer overflow in the PAN-OS User-ID Authentication Portal, root RCE, no patch until May 13. CISA added it to the Known Exploited Vulnerabilities catalog on May 6. We wrote about the CVE and the broader pattern of monthly security gateway RCEs this year (BeyondTrust Feb, Citrix Mar, SonicWall Apr). Post: https://zeroport.com/blog/pan-os-cve-2026-0300-pre-auth-rce