CVE-2026-0300: Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability

#paloaltonetworks #panos #cybersecurity #vulnerability

CVE ID

CVE-2026-0300

Vulnerability Name

Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability

Project: Palo Alto Networks
Product: PAN-OS

Date

Date Added: 2026-05-06
Due Date: 2026-05-09

Description

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.

Known To Be Used in Ransomware Campaigns?

Unknown

Action

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.