CVE-2026-103899: EU VAT Assistant for WooCommerce stored cross-site scripting (XSS) vulnerability

high 7.2 published 2026-10-17 · updated 2026-10-19

Affected versions: 2.1.30.260413 and older
Fixed in: 2.2.0.261001 *
Latest version: 2.2.0.261001
Severity: High · CVSS 7.2
Active installs: 5,000+
Type: Stored cross-site scripting (XSS)

* The source does not name a fixed version; this is the first wordpress.org release after the last affected version.

What an attacker needs

Access: None. No account or login is needed.

CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

What to do now

Update EU VAT Assistant for WooCommerce to 2.2.0.261001 or newer: Dashboard → Updates, or Plugins → “update now”.
If you cannot update right away, deactivate it until you can.
Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
Not sure which version you run? Check your version against every known EU VAT Assistant for WooCommerce issue. With WP-CLI: wp plugin get woocommerce-eu-vat-assistant --field=version.
If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.

The advisory

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.

Description from the CVE record, published by Wordfence (the CVE Numbering Authority), via the NVD entry for CVE-2026-103899.

References

NVD CVE-2026-103899 nvd.nist.gov
Wordfence advisory www.wordfence.com
Plugin source plugins.trac.wordpress.org

Ran an affected version? Check your site for signs of a hack

The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.

Where this data comes from

CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Versions and install counts: wordpress.org/plugins/woocommerce-eu-vat-assistant (Plugins API), fetched 2026-11-04.
The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.