CVE-2026-0300
Palo Alto Networks PAN-OS
Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability
What it is
Palo Alto Networks PAN-OS contains an out-of-bounds write vulnerability in the User-ID Authentication Portal (aka Captive Portal) service that can allow an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Until the vendor releases an official fix, the following workaround should be implemented: - Restrict User-ID Authentication Portal access to only trusted zones. - Disable User-ID Authentication Portal if not required. 5/13/2026: Palo Alto has released a variety of patches. If these are relevant to your environment, please apply the designated patch.
Vendor notices and references
Description and required action as published by CISA. Full record at NVD.
Other Palo Alto Networks entries on the list
- PAN-OS Palo Alto Networks PAN-OS Code Injection Vulnerability CVE-2026-0322 · Oct 14, 2026
- PAN-OS Palo Alto Networks PAN-OS Authentication Bypass Vulnerability CVE-2026-0257 · May 29, 2026
- PAN-OS Palo Alto Networks PAN-OS File Read Vulnerability CVE-2025-0111 · Feb 20, 2025
- PAN-OS Palo Alto Networks PAN-OS Authentication Bypass Vulnerability CVE-2025-0108 · Feb 18, 2025
- PAN-OS Palo Alto Networks PAN-OS Malicious DNS Packet Vulnerability CVE-2024-3393 · Dec 30, 2024
- PAN-OS Palo Alto Networks PAN-OS Management Interface OS Command Injection Vulnerability CVE-2024-9474 · Nov 18, 2024