CVE-2025-59593: Colibri Page Builder Stored XSS Vulnerability

CVE-2025-59593 Overview

CVE-2025-59593 is a stored Cross-Site Scripting (XSS) vulnerability in the Extend Themes Colibri Page Builder plugin for WordPress [CWE-79]. The flaw affects all versions up to and including 1.0.334. An authenticated attacker with high privileges can inject malicious scripts that persist in the WordPress database. Stored payloads execute in the browsers of other users who view affected pages. Exploitation requires user interaction, and the scope change in the CVSS vector reflects impact beyond the vulnerable component.

Critical Impact
Authenticated attackers can inject persistent JavaScript that executes against site visitors and administrators, enabling session theft, defacement, or redirection to attacker-controlled resources.

Affected Products

Extend Themes Colibri Page Builder (WordPress plugin)
All versions from n/a through < 1.0.334
WordPress sites running the vulnerable colibri-page-builder plugin

Discovery Timeline

2025-10-22 - CVE-2025-59593 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-59593

Vulnerability Analysis

The vulnerability is a stored XSS flaw classified under [CWE-79], Improper Neutralization of Input During Web Page Generation. The Colibri Page Builder plugin fails to properly sanitize or encode user-supplied input before rendering it in generated web pages. Attacker-controlled HTML and JavaScript persist in the WordPress database and execute when administrators or site visitors load the affected page.

The scope change in the attack means payloads can act on components beyond the plugin itself, including the surrounding WordPress session context. Successful exploitation can lead to session cookie theft, administrative account takeover, forced redirects, or injection of secondary payloads such as cryptocurrency miners or phishing content.

Root Cause

The root cause is missing or insufficient output encoding in the page builder's rendering logic. Input accepted through builder fields is written to the database and later echoed into the HTML response without context-aware escaping. Standard WordPress functions such as wp_kses_post() or esc_html() are not consistently applied to the affected fields.

Attack Vector

Exploitation requires an authenticated user with elevated privileges to create or modify content using the Colibri Page Builder. The attacker injects a JavaScript payload into a builder-controlled field. The payload is stored and executes when another user, typically an administrator or site visitor, loads the page. User interaction is required to trigger the stored script.

No public proof-of-concept exploit is listed, and the vulnerability is not present in the CISA Known Exploited Vulnerabilities catalog. See the Patchstack Vulnerability Report for additional technical context.

Detection Methods for CVE-2025-59593

Indicators of Compromise

Unexpected <script>, onerror, onload, or javascript: strings inside WordPress postmeta or posts rows associated with Colibri Page Builder content.
Outbound requests from administrator browser sessions to unfamiliar domains after loading pages built with Colibri.
New or modified administrator accounts following edits made by users with page-builder access.
Browser console errors or Content Security Policy violations on pages rendered by the plugin.

Detection Strategies

Query the WordPress database for Colibri-managed content containing HTML event handlers or script tags that should not appear in builder fields.
Review web server access logs for POST requests to admin-ajax.php or REST endpoints associated with colibri-page-builder from non-administrative sessions.
Compare current plugin files and database content against a known-good backup to identify unauthorized modifications.

Monitoring Recommendations

Enable WordPress audit logging to capture content changes made through the page builder, including the user, timestamp, and field modified.
Monitor administrator session activity for anomalous requests originating from pages that render Colibri content.
Alert on creation of new privileged WordPress users or changes to the wp_optionssiteurl and home values.

How to Mitigate CVE-2025-59593

Immediate Actions Required

Update Colibri Page Builder to a version later than 1.0.334 once the vendor releases a fixed build.
Audit all users with Editor, Administrator, or page-builder access and remove unnecessary privileged accounts.
Review existing pages created or edited with Colibri Page Builder for injected scripts and remove any unauthorized content.
Rotate administrator credentials and invalidate active sessions if suspicious builder activity is identified.

Patch Information

The vulnerability affects Colibri Page Builder versions through < 1.0.334. Apply the fixed release published by Extend Themes as soon as it is available. Monitor the Patchstack advisory for the fixed version number and corresponding WordPress plugin repository update.

Workarounds

Restrict page-builder access to a minimal set of trusted administrators until the patched version is deployed.
Deploy a Web Application Firewall rule to block requests containing script tags or JavaScript event handlers in Colibri builder fields.
Implement a strict Content Security Policy that disallows inline scripts to reduce the impact of stored XSS payloads.
Disable the plugin on production sites if trusted editorial workflows cannot be enforced.

bash

# Example: enforce a baseline Content Security Policy via Apache
# Add to the site's VirtualHost or .htaccess
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'"