---
title: "CVE-2026-103899: EU VAT Assistant for WooCommerce - Stored XSS & Privilege Escalation"
description: "EU VAT Assistant for WooCommerce <= 2.1.30.260413 contains a stored cross-site scripting caused by insufficient input sanitization and output escaping in 'vat_number' parameter, letting unauthenticated attackers execute scripts in admin context, exploit requires victim admin to view injected order."
url: https://panop.io/threat-heartbeat/CVE-2026-103899/
---

# CVE-2026-103899 EU VAT Assistant for WooCommerce - Stored XSS & Privilege Escalation

EU VAT Assistant for WooCommerce <= 2.1.30.260413 contains a stored cross-site scripting caused by insufficient input sanitization and output escaping in 'vat\_number' parameter, letting unauthenticated attackers execute scripts in admin context, exploit requires victim admin to view injected order.

CVSS base score 7.2 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.24% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-103899)

## Details

Type

Stored XSS

Impact

Stored XSS, Privilege Escalation

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Published

17 October 2026

Updated

19 October 2026

Weakness

[CWE-79](https://cwe.mitre.org/data/definitions/79.html)

## Vendor fix

Update to a version later than 2.1.30.260413 or the latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-103899](https://nvd.nist.gov/vuln/detail/CVE-2026-103899)
- [https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/order/order.php#L56](https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/order/order.php#L56)
- [https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/plugin-main.php#L1655](https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/plugin-main.php#L1655)
- [https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/plugin-main.php#L901](https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/plugin-main.php#L901)
- [https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/views/admin/order-vat-info-box.php#L173](https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/views/admin/order-vat-info-box.php#L173)
- [https://www.wordfence.com/threat-intel/vulnerabilities/id/e2cd7c07-e119-4064-a7a9-08c81409f90a?source=cve](https://www.wordfence.com/threat-intel/vulnerabilities/id/e2cd7c07-e119-4064-a7a9-08c81409f90a?source=cve)
- [https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/integration/admin/orders\_integration.php#L238](https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/integration/admin/orders_integration.php#L238)
- [https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/integration/vat\_number\_validation/validators/vat\_number\_validator.php#L132](https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/integration/vat_number_validation/validators/vat_number_validator.php#L132)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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