PatchSiren cyber security CVE debrief

CVE-2026-0256 Palo Alto Networks CVE debrief

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.

Vendor: Palo Alto Networks
Product: Cloud NGFW
CVSS: MEDIUM 5.2
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-05-12
Original CVE updated: 2026-07-02
Advisory published: 2026-05-12
Advisory updated: 2026-07-02

Who should care

Administrators and users of Palo Alto Networks PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series) should be aware of this vulnerability.

Technical summary

The vulnerability has a CVSS score of 4.4 and a severity of MEDIUM. The CVSS vector is 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.

Defensive priority

MEDIUM

Recommended defensive actions

Apply the patch or update provided by Palo Alto Networks to fix the vulnerability.
Restrict access to the web interface to prevent malicious administrators from storing JavaScript payloads.

Evidence notes

The vendor is Palo Alto Networks, as indicated by the evidence from reference_domain_candidate.

Sources and references

Verified primary and authoritative sources

CVE-2026-0256 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2026-0256

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2026-0256 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2026-0256

NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Source reference
Unverified legacy reference

URL: https://security.paloaltonetworks.com/CVE-2026-0256

[email protected]
Source reference
Unverified legacy reference

URL: https://cert-portal.siemens.com/productcert/html/ssa-967325.html

0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.