Executive brief
The User Profile Builder WordPress plugin contains a vulnerability in its optional "Format Date" shortcode that fails to properly escape user input. Contributors and higher-privileged users can inject malicious code that executes in the browsers of anyone viewing the affected content, including administrators, potentially leading to account takeover or data theft.
Technical details
This is a Stored Cross-Site Scripting (XSS) vulnerability in the wppb-format-date shortcode of User Profile Builder. The root cause is insufficient output escaping of the shortcode's date and format attributes. The vulnerability exploits a timing window in WordPress shortcode processing: post content is sanitized at save time (before the shortcode is rendered), but shortcode attributes containing escaped entities like \x3c and \x3e are expanded at render time, bypassing the initial sanitization. A contributor (the minimum role needed to create posts) can craft a malicious shortcode and store it in post content; when any user (including administrators) views the post, the unescaped XSS payload executes in their browser session. The shortcode is disabled by default, requiring administrator enablement. Fixed in version 4.0.1.
Affected products
- Cozmoslabs User Profile Builder before 4.0.1
Timeline
- 2026-08-27: disclosed
- 2026: patched: version 4.0.1 released