CVE-2026-0279 pan-os vulnerability
Multiple cross site scripting vulnerabilities in the User-ID™ Authentication Portal (aka Captive Portal) service, GlobalProtect™ gateway/portal features and Clientless VPN of Palo Alto Networks PAN-OS® software enables a malicious unauthenticated user to store or execute malicious JavaScript payload. The security risk posed by this issue is minimized when the management interface and access to the User-ID™ Authentication Portal is restricted to only trusted internal IP addresses according to our recommended best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 . This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series). Cloud NGFW is not affected by this vulnerability.
Quick answer
paloaltonetworks pan-os should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- Review vendor advisory for affected versions.
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
Palo Alto Networks PAN-OS is affected by CVE-2026-0279, a cross-site scripting risk. Multiple cross site scripting vulnerabilities in the User-ID™ Authentication Portal (aka Captive Portal) service, GlobalProtect™ gateway/portal features and Clientless VPN of Palo Alto Networks PAN-OS® software enables a malicious unauthenticated user to store or execute malicious JavaScript payload. The recommended remediation is to update to PAN-OS 12.1.8, 11.2.13, 11.1.16, 10.2.18-h8, Prisma Access 12.1.8, or the relevant supported Prisma Access hotfix for the deployed branch. Until the update is complete, restrict access to User-ID Authentication Portal, GlobalProtect, Clientless VPN, and management interfaces to trusted networks, review logs, and reduce exposure of the affected service or workflow.
- Inventory every deployment, package, appliance, container, service, and managed environment that uses Palo Alto Networks PAN-OS.
- Confirm the installed version and compare it with the affected versions listed in the source advisory and the source advisory for CVE-2026-0279.
- Apply the vendor-supported fix: update to PAN-OS 12.1.8, 11.2.13, 11.1.16, 10.2.18-h8, Prisma Access 12.1.8, or the relevant supported Prisma Access hotfix for the deployed branch.
- If the update cannot be applied immediately, restrict access to User-ID Authentication Portal, GlobalProtect, Clientless VPN, and management interfaces to trusted networks; disable unnecessary public access, endpoints, integrations, uploads, management interfaces, or high-risk features until patched.
- Review application, device, reverse-proxy, WAF, package manager, container, authentication, and audit logs for activity related to CVE-2026-0279.
- Rotate sessions, API tokens, service credentials, integration keys, and administrator passwords if logs or affected data indicate compromise, code execution, credential exposure, or unauthorized access.
- Clear caches, restart affected services, rebuild affected containers or appliances when appropriate, and remove temporary files, stored payloads, generated artifacts, or unsafe configuration created during exploitation attempts.
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Verify the fix
- Confirm Palo Alto Networks PAN-OS now reports PAN-OS 12.1.8, 11.2.13, 11.1.16, 10.2.18-h8, Prisma Access 12.1.8, or the relevant supported Prisma Access hotfix for the deployed branch or a later vendor-supported fixed release for the deployed branch.
- Verify the affected workflow no longer allows the behavior described in CVE-2026-0279, using a safe regression test or vendor-provided validation method.
- Review logs after remediation for continued exploit attempts, denial-of-service symptoms, suspicious redirects, unauthorized requests, file access, credential exposure, or configuration changes.
- Rerun a Fixnx scan and any product-specific scanner, package audit, device health check, or manual regression test relevant to the affected service.
- Document affected assets, fixed versions, mitigation decisions, validation evidence, and any cleanup or credential rotation performed.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-0279?
paloaltonetworks pan-os should be checked against the vendor advisory and trusted references linked on this page.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.