What the vulnerability does
01Description
The StatCounter – Free Real Time Visitor Stats plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.1.1 This is due to insufficient output escaping on the post author's nickname in the statcounter_addToTags() function. The function is hooked to wp_head and fires on every single post page. It retrieves the post author's nickname via the_author_meta() and echoes it directly into a JavaScript double-quoted string context inside a <script> block without applying esc_js() or any equivalent JavaScript-context escaping. This makes it possible for authenticated attackers with Author-level access and above to inject arbitrary web scripts into pages that will execute whenever any user (including unauthenticated visitors) accesses a post authored by the attacker.
Explanation of Vulnerability in Simple Terms
02Summary
StatCounter versions up to 2.1.1 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. An attacker with low-level privileges can inject code that executes in other users' browsers, potentially compromising their sessions or data.
What an attacker can do
03Attacker Capabilities
Inject malicious scripts that execute in other users' browsers, potentially stealing session data or performing actions on their behalf.
Potential impact on your site
04Site Impact
Authenticated users can inject scripts affecting other site visitors; session hijacking or unauthorized actions are possible.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege account on the site; no user interaction required from the victim.
Key dates
06Disclosure timeline
May 29, 2026
CVE published
May 29, 2026
Record updated
