CVE-2026-0256 PAN-OS: Stored Cross-Site Scripting (XSS) Vulnerability in the Web Interface

Medium 4.4 Published 13 May 2026 Updated 15 Oct 2026

A malicious authenticated administrator can inject JavaScript into the PAN-OS web interface, potentially compromising other users or the system.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2026-0256?

CVE-2026-0256 is a medium-severity cross-site scripting vulnerability in Paloaltonetworks Pan-Os, published on 13 May 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official 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.

Weakness: CWE-79

Which versions are affected by CVE-2026-0256?

It affects 2 products.

Products include Paloaltonetworks Pan-Os, Siemens Ruggedcom Ape1808 Firmware.

How do I fix CVE-2026-0256?

No fix has been published for CVE-2026-0256 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-0256 being exploited?

There is no known exploitation of CVE-2026-0256 in the wild and no public exploit code.

All Paloaltonetworks Pan-Os vulnerabilities

Sources

Also known as GHSA-q845-rv2h-x553.