What the vulnerability does
01Description
The Post Category Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'postcategorygallery' shortcode in versions up to, and including, 1.0.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (such as total_width, color_scheme, and caption_font_size) inside the sc_horcatbar() function, which are concatenated directly into HTML attribute values. 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
Post Categories Gallery versions up to 1.0.0 contain a cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious scripts. The vulnerability has a changed scope, meaning injected code can affect other users and site functionality. An attacker with low-level account access can craft malicious input that executes in other users' browsers when they view affected pages.
What an attacker can do
03Attacker Capabilities
Inject JavaScript that runs in other users' browsers and affects site functionality.
Potential impact on your site
04Site Impact
Authenticated users can inject malicious scripts affecting other visitors and site operations.
Conditions required to exploit
05Prerequisites
Attacker needs a low-privilege account on the site; no user interaction required.
Key dates
06Disclosure timeline
May 27, 2026
CVE published
May 27, 2026
Record updated
