CVE-2026-103899: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in daigo75 EU VAT Assistant for WooCommerce
Description
The EU VAT Assistant for WooCommerce WordPress plugin contains a stored cross-site scripting (XSS) vulnerability in the 'vat_number' parameter affecting all versions up to 2.1.30.260413. This vulnerability allows unauthenticated attackers to inject malicious scripts that execute in the administrator's browser when reviewing orders, potentially leading to privilege escalation and full site takeover through rogue administrator account creation.
CVSS v3.1
Score 7.2high
Affected software
daigo75
EU VAT Assistant for WooCommerce
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-103899 is a stored cross-site scripting vulnerability (CWE-79) in the EU VAT Assistant for WooCommerce plugin for WordPress. The flaw exists due to insufficient input sanitization and output escaping of the 'vat_number' parameter in all versions up to and including 2.1.30.260413. An unauthenticated attacker can inject arbitrary web scripts that execute in the context of an administrator's browser when viewing an order in WooCommerce. This can lead to privilege escalation, including the creation of rogue administrator accounts and full site takeover.
Potential Impact
Successful exploitation allows unauthenticated attackers to execute arbitrary scripts in the administrator's browser context, leading to privilege escalation and potentially full site compromise. The attacker can create rogue administrator accounts, effectively taking over the WordPress site.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to order editing pages to trusted administrators only and consider applying web application firewall (WAF) rules to detect and block malicious input targeting the 'vat_number' parameter.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Wordfence
- Date Reserved
- 2026-10-01T13:55:27.399Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad2f3b02cdf04f656deaea2
Added to database: 10/17/2026, 04:04:00 UTC
Last enriched: 10/17/2026, 04:18:32 UTC
Last updated: 10/17/2026, 04:18:32 UTC
Views: 4
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