CVE-2026-0300: listed in the CISA KEV catalog

CVE-2026-0300 · EPSS 32% · KEV 2026-05-06

A buffer overflow vulnerability in the User-ID™ Authentication Portal (aka Captive Portal) service of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to execute arbitrary code with root privileges on the PA-Series and VM-Series firewalls by sending specially crafted packets. The risk of this issue is greatly reduced if you secure access to the User-ID™ Authentication Portal per the best practice guidelines https://knowledgebase.paloaltonetworks.com/KCSArticleDetail by restricting access to only trusted internal IP addresses. Prisma Access, Cloud NGFW and Panorama appliances are not impacted by this vulnerability.

Is CVE-2026-0300 exploited?

• Listed in the CISA KEV catalog on 2026-05-06.
• Federal remediation due 2026-05-09.
• Past that date by 98 days.
• EPSS puts exploitation in the next 30 days at 32%.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2026-0300

• Critical Manufacturing Gear Exposed by PAN-OS Flaw (2026-05-20)

Primary sources

• NVD record
• CISA KEV catalog

What this record does not say

• No CVSS score from NVD.
• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.