CVE-2026-4067
Received Received - Intake

Stored XSS in Ad Short WordPress Plugin via 'client' Attribute

Publication date: 2026-03-21

Last updated on: 2026-03-21

Assigner: Wordfence

Description
The Ad Short plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'ad' shortcode's 'client' attribute in all versions up to and including 2.0.1. This is due to insufficient input sanitization and output escaping on the 'client' shortcode attribute. The ad_func() shortcode handler at line 71 accepts a 'client' attribute via shortcode_atts() and directly concatenates it into a double-quoted HTML attribute (data-ad-client) at line 130 without applying esc_attr() or any other sanitization. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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Meta Information

Published
2026-03-21
Last Modified
2026-03-21
Generated
2026-07-06
AI Q&A
2026-03-21
EPSS Evaluated
2026-07-04
NVD
CVE-2026-4067
EUVD
EUVD-2026-13999

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wordfence ad_short to 2.0.1 (inc)

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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Impact Analysis

This vulnerability allows attackers with Contributor-level access or higher to inject arbitrary malicious scripts into pages.

When other users visit these pages, the injected scripts execute in their browsers, potentially leading to theft of sensitive information, session hijacking, or other malicious actions.

Because the attack is stored, the malicious code persists on the site and affects all users who access the compromised content.

Mitigation Strategies

To mitigate this vulnerability, update the Ad Short plugin for WordPress to a version later than 2.0.1 where the issue is fixed.

Ensure that only trusted users have Contributor-level access or higher, as the vulnerability requires authenticated users with such privileges to exploit.

Consider temporarily disabling the Ad Short plugin if an immediate update is not possible.

Executive Summary

The Ad Short plugin for WordPress has a Stored Cross-Site Scripting (XSS) vulnerability in its 'ad' shortcode's 'client' attribute in all versions up to and including 2.0.1.

This vulnerability occurs because the plugin does not properly sanitize or escape the input provided in the 'client' attribute before inserting it into the HTML output.

Specifically, the ad_func() shortcode handler accepts the 'client' attribute and directly inserts it into a double-quoted HTML attribute (data-ad-client) without using any sanitization functions like esc_attr().

As a result, authenticated users with Contributor-level access or higher can inject malicious scripts that will be stored and executed whenever any user views the affected page.

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