Vulnerability Database

383,371

Total vulnerabilities in the database

CVE-2026-0300 — paloaltonetworks / pan-os

Out-of-bounds Write

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.

  • Published: May 6, 2026
  • Updated: Sep 13, 2026
  • CVE: CVE-2026-0300
  • Severity: Critical
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Critical
  • Score: 9.8
  • AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWEs:

Software Affected versions
paloaltonetworks / pan-os = 10.2.0
paloaltonetworks / pan-os = 10.2.1
paloaltonetworks / pan-os = 10.2.2
paloaltonetworks / pan-os = 10.2.3
paloaltonetworks / pan-os = 10.2.4
paloaltonetworks / pan-os = 10.2.5
paloaltonetworks / pan-os = 10.2.6
paloaltonetworks / pan-os = 10.2.7
paloaltonetworks / pan-os = 10.2.7-h1
paloaltonetworks / pan-os = 10.2.7-h12
paloaltonetworks / pan-os = 10.2.7-h16
paloaltonetworks / pan-os = 10.2.7-h19
paloaltonetworks / pan-os = 10.2.7-h21
paloaltonetworks / pan-os = 10.2.7-h24
paloaltonetworks / pan-os = 10.2.7-h3
paloaltonetworks / pan-os = 10.2.7-h32
paloaltonetworks / pan-os = 10.2.7-h6
paloaltonetworks / pan-os = 10.2.7-h8
paloaltonetworks / pan-os = 10.2.8
paloaltonetworks / pan-os = 10.2.9
paloaltonetworks / pan-os = 10.2.10
paloaltonetworks / pan-os = 10.2.10-h10
paloaltonetworks / pan-os = 10.2.10-h12
paloaltonetworks / pan-os = 10.2.10-h14
paloaltonetworks / pan-os = 10.2.10-h17
paloaltonetworks / pan-os = 10.2.10-h18
paloaltonetworks / pan-os = 10.2.10-h2
paloaltonetworks / pan-os = 10.2.10-h21
paloaltonetworks / pan-os = 10.2.10-h27
paloaltonetworks / pan-os = 10.2.10-h3
paloaltonetworks / pan-os = 10.2.10-h30
paloaltonetworks / pan-os = 10.2.10-h31
paloaltonetworks / pan-os = 10.2.10-h4
paloaltonetworks / pan-os = 10.2.10-h5
paloaltonetworks / pan-os = 10.2.10-h7
paloaltonetworks / pan-os = 10.2.10-h9
paloaltonetworks / pan-os = 10.2.11
paloaltonetworks / pan-os = 10.2.12
paloaltonetworks / pan-os = 10.2.13
paloaltonetworks / pan-os = 10.2.13-h1
paloaltonetworks / pan-os = 10.2.13-h10
paloaltonetworks / pan-os = 10.2.13-h16
paloaltonetworks / pan-os = 10.2.13-h18
paloaltonetworks / pan-os = 10.2.13-h2
paloaltonetworks / pan-os = 10.2.13-h3
paloaltonetworks / pan-os = 10.2.13-h4
paloaltonetworks / pan-os = 10.2.13-h5
paloaltonetworks / pan-os = 10.2.13-h7
paloaltonetworks / pan-os = 10.2.14
paloaltonetworks / pan-os = 10.2.15
paloaltonetworks / pan-os = 10.2.16
paloaltonetworks / pan-os = 10.2.16-h1
paloaltonetworks / pan-os = 10.2.16-h4
paloaltonetworks / pan-os = 10.2.16-h6
paloaltonetworks / pan-os = 10.2.17
paloaltonetworks / pan-os = 10.2.18
paloaltonetworks / pan-os = 10.2.18-h1
paloaltonetworks / pan-os = 10.2.18-h5
paloaltonetworks / pan-os = 11.1.0
paloaltonetworks / pan-os = 11.1.1
paloaltonetworks / pan-os = 11.1.2
paloaltonetworks / pan-os = 11.1.3
paloaltonetworks / pan-os = 11.1.4
paloaltonetworks / pan-os = 11.1.4-h1
paloaltonetworks / pan-os = 11.1.4-h13
paloaltonetworks / pan-os = 11.1.4-h15
paloaltonetworks / pan-os = 11.1.4-h16
paloaltonetworks / pan-os = 11.1.4-h17
paloaltonetworks / pan-os = 11.1.4-h18
paloaltonetworks / pan-os = 11.1.4-h25
paloaltonetworks / pan-os = 11.1.4-h27
paloaltonetworks / pan-os = 11.1.4-h32
paloaltonetworks / pan-os = 11.1.4-h4
paloaltonetworks / pan-os = 11.1.4-h7
paloaltonetworks / pan-os = 11.1.4-h9
paloaltonetworks / pan-os = 11.1.5
paloaltonetworks / pan-os = 11.1.6
paloaltonetworks / pan-os = 11.1.6-h1
paloaltonetworks / pan-os = 11.1.6-h10
paloaltonetworks / pan-os = 11.1.6-h14
paloaltonetworks / pan-os = 11.1.6-h17
paloaltonetworks / pan-os = 11.1.6-h19
paloaltonetworks / pan-os = 11.1.6-h2
paloaltonetworks / pan-os = 11.1.6-h20
paloaltonetworks / pan-os = 11.1.6-h21
paloaltonetworks / pan-os = 11.1.6-h22
paloaltonetworks / pan-os = 11.1.6-h23
paloaltonetworks / pan-os = 11.1.6-h25
paloaltonetworks / pan-os = 11.1.6-h29
paloaltonetworks / pan-os = 11.1.6-h3
paloaltonetworks / pan-os = 11.1.6-h4
paloaltonetworks / pan-os = 11.1.6-h5
paloaltonetworks / pan-os = 11.1.6-h6
paloaltonetworks / pan-os = 11.1.6-h7
paloaltonetworks / pan-os = 11.1.7
paloaltonetworks / pan-os = 11.1.7-h1
paloaltonetworks / pan-os = 11.1.7-h2
paloaltonetworks / pan-os = 11.1.7-h4
paloaltonetworks / pan-os = 11.1.8
paloaltonetworks / pan-os = 11.1.9
paloaltonetworks / pan-os = 11.1.10
paloaltonetworks / pan-os = 11.1.10-h1
paloaltonetworks / pan-os = 11.1.10-h10
paloaltonetworks / pan-os = 11.1.10-h12
paloaltonetworks / pan-os = 11.1.10-h21
paloaltonetworks / pan-os = 11.1.10-h4
paloaltonetworks / pan-os = 11.1.10-h5
paloaltonetworks / pan-os = 11.1.10-h7
paloaltonetworks / pan-os = 11.1.10-h9
paloaltonetworks / pan-os = 11.1.11
paloaltonetworks / pan-os = 11.1.12
paloaltonetworks / pan-os = 11.1.13
paloaltonetworks / pan-os = 11.1.13-h1
paloaltonetworks / pan-os = 11.1.13-h2
paloaltonetworks / pan-os = 11.1.13-h3
paloaltonetworks / pan-os = 11.1.14
paloaltonetworks / pan-os = 11.2.0
paloaltonetworks / pan-os = 11.2.1
paloaltonetworks / pan-os = 11.2.2
paloaltonetworks / pan-os = 11.2.3
paloaltonetworks / pan-os = 11.2.4
paloaltonetworks / pan-os = 11.2.4-h1
paloaltonetworks / pan-os = 11.2.4-h10
paloaltonetworks / pan-os = 11.2.4-h11
paloaltonetworks / pan-os = 11.2.4-h12
paloaltonetworks / pan-os = 11.2.4-h14
paloaltonetworks / pan-os = 11.2.4-h15
paloaltonetworks / pan-os = 11.2.4-h2
paloaltonetworks / pan-os = 11.2.4-h4
paloaltonetworks / pan-os = 11.2.4-h5
paloaltonetworks / pan-os = 11.2.4-h6
paloaltonetworks / pan-os = 11.2.4-h7
paloaltonetworks / pan-os = 11.2.4-h8
paloaltonetworks / pan-os = 11.2.4-h9
paloaltonetworks / pan-os = 11.2.5
paloaltonetworks / pan-os = 11.2.6
paloaltonetworks / pan-os = 11.2.7
paloaltonetworks / pan-os = 11.2.7-h1
paloaltonetworks / pan-os = 11.2.7-h10
paloaltonetworks / pan-os = 11.2.7-h11
paloaltonetworks / pan-os = 11.2.7-h12
paloaltonetworks / pan-os = 11.2.7-h2
paloaltonetworks / pan-os = 11.2.7-h3
paloaltonetworks / pan-os = 11.2.7-h4
paloaltonetworks / pan-os = 11.2.7-h7
paloaltonetworks / pan-os = 11.2.7-h8
paloaltonetworks / pan-os = 11.2.8
paloaltonetworks / pan-os = 11.2.9
paloaltonetworks / pan-os = 11.2.10
paloaltonetworks / pan-os = 11.2.10-h1
paloaltonetworks / pan-os = 11.2.10-h2
paloaltonetworks / pan-os = 11.2.10-h3
paloaltonetworks / pan-os = 11.2.10-h4
paloaltonetworks / pan-os = 11.2.10-h5
paloaltonetworks / pan-os = 11.2.11
paloaltonetworks / pan-os = 12.1.2
paloaltonetworks / pan-os = 12.1.3
paloaltonetworks / pan-os = 12.1.4
paloaltonetworks / pan-os = 12.1.4-h2
paloaltonetworks / pan-os = 12.1.4-h3
paloaltonetworks / pan-os = 12.1.5
paloaltonetworks / pan-os = 12.1.6

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.