CVE-2026-0300
Palo Alto Networks PAN-OS Out-of-bounds Write Vulnerability
Palo Alto Networks · PAN-OS
Vulnerability details
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.
Added to CISA KEV: 2026-05-06
Ransomware campaign use: Unknown
CISA due date: 2026-05-09
Defensive guidance from CISA
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.
This is the source's required-action field, not an independently validated patch procedure. Refer to the vendor for exact affected versions and fixes.
Source catalog date: 2026-11-06T19:44:45.1797Z · Last retrieved: 2026-11-06 21:02:26 UTC