What the vulnerability does
01Description
The Cryptocurrency Prijsvergelijking Widget plugin for WordPress is vulnerable to Stored Cross-Site Scripting in version 1.0. This is due to insufficient output escaping in the as_get_coin_shortcode() function, which renders the 'width' (and 'height') shortcode attribute directly into the style attribute of an <iframe> element without applying any escaping function such as esc_attr(). An attacker-controlled value like '100px;"onload="alert(1)" x="' terminates the style attribute prematurely and injects an arbitrary HTML attribute into the iframe tag. 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
The Cryptocurrency Prijsvergelijking Widget contains a cross-site scripting (XSS) vulnerability in versions up to 1.0. An attacker with low-level user privileges can inject malicious scripts that execute in other users' browsers, potentially stealing session data or performing actions on their behalf. The vulnerability affects the entire site scope due to how the widget renders untrusted input.
What an attacker can do
03Attacker Capabilities
Inject malicious JavaScript that runs in other users' browsers and affects the entire site.
Potential impact on your site
04Site Impact
Authenticated attackers can compromise other users' sessions and perform unauthorized actions across your site.
Conditions required to exploit
05Prerequisites
Attacker needs a low-privilege user account; no user interaction required from victims.
Key dates
06Disclosure timeline
May 27, 2026
CVE published
May 27, 2026
Record updated
