PAN-OS: Stored Cross-Site Scripting (XSS) Vulnerability in the Web Interface
Summary
| CVE | CVE-2026-0256 |
|---|---|
| State | PUBLISHED |
| Assigner | palo_alto |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-13 19:17:00 UTC |
| Updated | 2026-05-14 16:21:23 UTC |
| Description | A stored cross-site scripting (XSS) vulnerability in Palo Alto Networks PAN-OS® software enables a malicious authenticated administrator to store a JavaScript payload using the web interface. This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series). Cloud NGFW and Prisma® Access are not impacted by this vulnerability. |
Risk And Classification
Primary CVSS: v4.0 4.4 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:U/V:D/RE:M/U:Amber
EPSS: 0.000570000 probability, percentile 0.177010000 (date 2026-05-25)
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 4.4 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/C... |
| 4.0 | CNA | CVSS | 4.4 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/A... |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:U/V:D/RE:M/U:Amber
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Palo Alto Networks | Cloud NGFW | unaffected All custom | Not specified |
| CNA | Palo Alto Networks | PAN-OS | affected 12.1.0 12.1.7 custom | Not specified |
| CNA | Palo Alto Networks | PAN-OS | affected 11.2.0 11.2.12 custom | Not specified |
| CNA | Palo Alto Networks | PAN-OS | affected 11.1.0 11.1.15 custom | Not specified |
| CNA | Palo Alto Networks | PAN-OS | affected 10.2.0 10.2.18-h6 custom | Not specified |
| CNA | Palo Alto Networks | Prisma Access | unaffected All custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| security.paloaltonetworks.com/CVE-2026-0256 | [email protected] | security.paloaltonetworks.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Palo Alto Networks thanks our internal security research teams for discovering and reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-05-13T16:00:00.000Z | Initial publication. |
Solutions
CNA: VERSION MINOR VERSION RANGE SUGGESTED SOLUTION Cloud NGFW No action needed. PAN-OS 12.1 12.1.5 through 12.1.6 Upgrade to 12.1.7 or later. 12.1.2 through 12.1.4-h* Upgrade to 12.1.4-h5 or 12.1.7 or later. PAN-OS 11.2 11.2.11 or later Upgrade to 11.2.12 or later. 11.2.8 through 11.2.10-h* Upgrade to 11.2.10-h6 or 11.2.12 or later. 11.2.5 through 11.2.7-h* Upgrade to 11.2.7-h13 or 11.2.12 or later. 11.2.0 through 11.2.4-h* Upgrade to 11.2.4-h17 or 11.2.12 or later. PAN-OS 11.1 11.1.14 or later Upgrade to 11.1.15 or later. 11.1.11 through 11.1.13-h* Upgrade to 11.1.13-h5 or 11.1.15 or later. 11.1.8 through 11.1.10-h* Upgrade to 11.1.10-h25 or 11.1.15 or later. 11.1.7 through 11.1.7-h* Upgrade to 11.1.7-h6 or 11.1.15 or later. 11.1.5 through 11.1.6-h* Upgrade to 11.1.6-h32 or 11.1.15 or later. 11.1.0 through 11.1.4-h* Upgrade to 11.1.4-h33 or 11.1.15 or later. PAN-OS 10.2 10.2.17 through 10.2.18-h* Upgrade to 10.2.18-h6 or later. 10.2.14 through 10.2.16-h* Upgrade to 10.2.16-h7 or 10.2.18-h6 or later. 10.2.11 through 10.2.13-h* Upgrade to 10.2.13-h21 or 10.2.18-h6 or later. 10.2.8 through 10.2.10-h* Upgrade to 10.2.10-h36 or 10.2.18-h6 or later. 10.2.0 through 10.2.7-h* Upgrade to 10.2.7-h34 or 10.2.18-h6 or later. All older Upgrade to a supported fixed version. unsupported PAN-OS versions Prisma Access No action needed.
Workarounds
CNA: Customers with a Threat Prevention subscription can block attacks for this vulnerability by enabling Threat ID 510020 (from Applications and Threats content version 9100-10044 and later). For these Threat IDs to protect against attacks for this vulnerability: * Route incoming traffic for the MGT port through a DP port (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#id59206398-3dab-4b2f-9b4b-7ea500d036ba), e.g., enabling management profile on a DP interface for management access. * Replace the Certificate for Inbound Traffic Management (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#id112f7714-8995-4496-bbf9-781e63dec71c). * Decrypt inbound traffic to the management interface (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#idbbd82587-17a2-42b4-9245-d3714e1e13a2) so the firewall can inspect it (https://docs.paloaltonetworks.com/best-practices/10-1/administrative-access-best-practices/administrative-access-best-practices/deploy-administrative-access-best-practices#idbbd82587-17a2-42b4-9245-d3714e1e13a2). * Enable threat prevention on the inbound traffic to management services.
Exploits
CNA: Palo Alto Networks is not aware of any malicious exploitation of this issue.