What the vulnerability does
01Description
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.
Explanation of Vulnerability in Simple Terms
02Summary
Ad Short versions 2.0.1 and earlier contain a cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious scripts affecting other users. The vulnerability has a changed scope, meaning the impact extends beyond the vulnerable component itself. Low-privileged accounts can exploit this without user interaction.
What an attacker can do
03Attacker Capabilities
Inject malicious scripts that execute in other users' browsers and affect site functionality.
Potential impact on your site
04Site Impact
Authenticated users can inject scripts affecting other visitors; may compromise user sessions or site data.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privileged account on the site; no user interaction required.
Key dates
06Disclosure timeline
March 21, 2026
CVE published
April 8, 2026
Record updated
