CVE-2026-103899
Received Received - Intake

Stored XSS in EU VAT Assistant for WooCommerce Plugin

Publication date: 2026-10-17

Last updated on: 2026-10-17

Assigner: Wordfence

Description
The EU VAT Assistant for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'vat_number' parameter in all versions up to, and including, 2.1.30.260413 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The stored payload executes in the administrator's browser context when reviewing an order via WooCommerce → Orders → Edit Order, enabling privilege escalation up to and including full site takeover via rogue administrator account creation.

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Meta Information

Published
2026-10-17
Last Modified
2026-10-17
Generated
2026-10-17
AI Q&A
2026-10-17
EPSS Evaluated
N/A
NVD
CVE-2026-103899
EUVD
EUVD-2026-103232

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
daigo75 EU VAT Assistant for WooCommerce 0

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This is a Stored Cross-Site Scripting (XSS) vulnerability in the EU VAT Assistant for WooCommerce plugin for WordPress. It exists in versions up to 2.1.30.260413 due to insufficient input sanitization and output escaping in the 'vat_number' parameter. Attackers can inject malicious scripts that execute when users access infected pages, particularly when an administrator reviews an order.

Detection Guidance

Check for the presence of the EU VAT Assistant for WooCommerce plugin versions up to and including 2.1.30.260413. Inspect the 'vat_number' parameter in WooCommerce orders for suspicious scripts. Review admin browser sessions for unexpected activity during order reviews.

Impact Analysis

Unauthenticated attackers can inject arbitrary scripts that execute in the administrator's browser when reviewing orders. This enables privilege escalation, potentially leading to full site takeover through the creation of rogue administrator accounts.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, including personal and financial information, which may violate GDPR and HIPAA compliance requirements. The stored XSS attack enables attackers to inject malicious scripts that can steal data or escalate privileges, potentially exposing regulated data to unauthorized parties.

Mitigation Strategies

Update the EU VAT Assistant for WooCommerce plugin to the latest version. If an update is unavailable, consider disabling the plugin temporarily. Implement input sanitization for the 'vat_number' parameter and review all admin accounts for unauthorized changes.

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