CVE-2026-103899
EU VAT Assistant for WooCommerce <= 2.1.30.260413 - Unauthenticated Stored Cross-Site Scripting via 'vat_number' Parameter
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.
INFO
Published Date :
Oct. 17, 2026, 4:16 a.m.
Last Modified :
Oct. 17, 2026, 4:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-103899
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update the EU VAT Assistant for WooCommerce plugin immediately.
- Review and sanitize all user inputs.
- Escape output correctly to prevent script injection.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-103899.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-103899 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-103899
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-103899 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-103899 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Oct. 17, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/103xxx/CVE-2026-103899.json">CVE-2026-103899</a> Added Reference https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/integration/admin/orders_integration.php#L238 Added Reference 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 Added Reference https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/lib/classes/order/order.php#L56 Added Reference https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/plugin-main.php#L1655 Added Reference https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/plugin-main.php#L901 Added Reference https://plugins.trac.wordpress.org/browser/woocommerce-eu-vat-assistant/tags/2.1.30.260413/src/views/admin/order-vat-info-box.php#L173 Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/e2cd7c07-e119-4064-a7a9-08c81409f90a?source=cve