Threat Intelligence / CVE / CVE-2026-0300

CVE-2026-0300

CISA KEVRansomware

CVSS 9.3 · EPSS 4.5% · Published 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.

Weaknesses (CWE)

CWE-787

Threats tracking this CVE

PAN-OS User-ID Authentication Portal RCE Zero-Day (CVE-2026-0300) — Active Exploitation on PA-Series & VM-Series Firewalls — CRITICAL

References

https://security.paloaltonetworks.com/CVE-2026-0300

Full detection coverage & IOCs for threats exploiting CVE-2026-0300 are available via the Threadlinqs MCP server (Purple tier). View plans →

Markdown version · Threadlinqs Intelligence