What the vulnerability does
01Description
The Easy Prism Syntax Highlighter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'code' (and 'c') shortcode in versions up to, and including, 1.0.2. This is due to insufficient input sanitization and output escaping on user supplied shortcode attributes in the shortcode() function, which concatenates the first positional attribute directly into the class attribute of the generated <pre>/<code> HTML without calling esc_attr() or any other escaping function. 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
Easy Prism Syntax Highlighter versions 1.0.2 and earlier contain a cross-site scripting vulnerability. An authenticated user with low privileges can inject malicious scripts that execute in other users' browsers, potentially affecting site visitors across different security contexts. The vulnerability requires an attacker to have a valid account but no user interaction from victims.
What an attacker can do
03Attacker Capabilities
Inject malicious JavaScript that runs in other users' browsers and affects site visitors.
Potential impact on your site
04Site Impact
Authenticated users can inject scripts affecting other visitors; may lead to credential theft or malware distribution.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege authenticated account; no victim interaction required.
Key dates
06Disclosure timeline
May 27, 2026
CVE published
May 27, 2026
Record updated
