dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 9 May 2026.
Pan OsOperating system · Paloaltonetworks

CVE-2026-0300

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
In the wild Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A buffer overflow vulnerability in the User-ID Authentication Portal (Captive Portal) service of PAN-OS allows unauthenticated attackers to send specially crafted packets and achieve arbitrary code execution with root privileges on affected PA-Series and VM-Series firewalls.

MitigationRestrict access to the User-ID Authentication Portal to only trusted internal IP addresses per best practice guidelines; apply vendor patches when available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Pan OsOperating system
Affected:= 10.2.0= 10.2.1= 10.2.2= 10.2.3= 10.2.4= 10.2.5= 10.2.6= 10.2.7= 10.2.8= 10.2.9= 10.2.10= 10.2.11
Ruggedcom Ape1808 FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check PAN-OS version
    Run 'show system info' on the CLI or view Device > Setup > Operations in the web interface to confirm the installed PAN-OS version
    Affected if Version is 10.2.0, 10.2.1, 10.2.2, 10.2.3, 10.2.4, 10.2.5, 10.2.6, 10.2.7, 10.2.8, 10.2.9, 10.2.10, or 10.2.11
  2. Verify Captive Portal status
    Navigate to Network > Captive Portal or Device > User Identification > Captive Portal Settings in the web UI, or run 'show user captive-portal status' in the CLI
    Affected if Captive Portal is enabled on the firewall
  3. Identify Captive Portal interface binding
    Review the Captive Portal configuration to determine which interfaces the service is bound to, typically found in the same Captive Portal settings area
    Affected if Captive Portal is bound to the management interface or any interface accessible from untrusted/external networks
  4. Assess network exposure of Captive Portal
    Check firewall traffic policies and interface configurations to determine if the Captive Portal service port (default 6080/6081) is reachable from untrusted or external network segments
    Affected if The Captive Portal service is exposed to networks that are not trusted internal IP addresses

You are affected if your firewall runs PAN-OS 10.2.0 through 10.2.11 AND the User-ID Authentication Portal (Captive Portal) feature is enabled and accessible from untrusted networks.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Restrict access to the User-ID Authentication Portal to only trusted internal IP addresses per best practice guidelines; apply vendor patches when available.

Fix this in Pan Os Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing6.0 h
  • Review / QA3.0 h
16.0 hours of engineering $2,780
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,448.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-0300 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-0300 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data