CVE-2026-0300 PAN-OS: Unauthenticated user initiated Buffer Overflow Vulnerability in User-ID™ Authentication Portal (Severity: CRITICAL)

Key Points:

• CVE-2026-0300 is a critical buffer overflow vulnerability in the User-ID™ Authentication Portal of Palo Alto Networks PAN-OS, allowing unauthenticated attackers to execute arbitrary code with root privileges.
• Affected systems include PA-Series and VM-Series firewalls running specific versions of PAN-OS (12.1, 11.2, 11.1, and 10.2). The risk is heightened when the portal is accessible from untrusted networks.
• Recommended actions include restricting access to the User-ID™ Authentication Portal to trusted internal IP addresses and disabling the portal if not needed.

Technical Details: This vulnerability allows attackers to exploit specially crafted packets to gain root access on vulnerable devices without requiring user interaction (CWE-787).

MITRE ATT&CK Techniques: None mentioned

IOCs Mentioned: None mentioned