PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-0266 Palo Alto Networks CVE debrief

CVE-2026-0266 is a cross-site scripting (XSS) vulnerability in Palo Alto Networks PAN-OS software. This vulnerability allows a malicious authenticated administrator to store a JavaScript payload using the web interface. The affected products include PA-Series and VM-Series firewalls and Panorama (virtual and M-Series). However, Cloud NGFW and Prisma Access are not affected by this vulnerability. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 1.1, indicating a low severity.

Vendor
Palo Alto Networks
Product
Cloud NGFW
CVSS
LOW 2.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-21
Advisory published
2026-07-14
Advisory updated
2026-07-21

Who should care

Administrators and security teams using Palo Alto Networks PAN-OS software on PA-Series and VM-Series firewalls and Panorama (virtual and M-Series) should be aware of this vulnerability and take necessary actions to mitigate it.

Technical summary

The vulnerability is caused by improper input validation in the web interface of Palo Alto Networks PAN-OS software, allowing an authenticated administrator to inject a JavaScript payload. The CVSS vector for this vulnerability is CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/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

Low

Recommended defensive actions

  • Apply the patch or update provided by Palo Alto Networks to fix the vulnerability.
  • Restrict access to the web interface to only trusted administrators.
  • Monitor the system for any suspicious activity.

Evidence notes

The CVE record was obtained from the official CVE website and the NVD detail page.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-0266 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-0266

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-0266 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-0266

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

Supplemental references

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.