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Response snapshot Oct 27, 2026, 02:06 UTC

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VulnerabilityCVE-2026-103899

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,...

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.

At a glance

Exploited
Not known
Severity
7.2 High (CVSS 3.1)
Chance of exploitation
0.2% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-103899 (opens a new tab)

What happened

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.

Scores and how they were measured

CVSS base severity

7.2

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.2%

Scored Percentile 15.1%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-103899 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-103899, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 19). 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,... (CVE-2026-103899). https://kevwire.com/record/CVE-2026-103899

MLA

"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,... (CVE-2026-103899)." KEVWire, 19 Oct. 2026, kevwire.com/record/CVE-2026-103899.

Chicago

KEVWire. "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,... (CVE-2026-103899)." Last modified October 19, 2026. https://kevwire.com/record/CVE-2026-103899.

Evidence summary (plain text)

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,... (Oct 17, 2026).
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.
CVSS 7.2 (version 3.1; evidence as of Oct 19, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-103899).
EPSS 0.2% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-103899&date=2026-10-26).
Sources:
NVD CVE-2026-103899: https://nvd.nist.gov/vuln/detail/CVE-2026-103899
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?pubStartDate=2026-10-12T13:35:55.142Z&pubEndDate=2026-10-26T13:35:55.142Z&resultsPerPage=500&startIndex=4500
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-103899&date=2026-10-26
Record ID: CVE-2026-103899.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Deferred. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

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Record details

Record detail