CVE-2026-4077: Ecover Builder For Dummies XSS Vulnerability

CVE-2026-4077 Overview

The Ecover Builder For Dummies plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the id parameter of the ecover shortcode in all versions up to and including 1.0. This vulnerability stems from insufficient input sanitization and output escaping on the user-supplied id shortcode attribute. Authenticated attackers with Contributor-level access and above can inject arbitrary web scripts into pages that will execute whenever a user accesses an injected page.

Critical Impact

Authenticated attackers can inject persistent malicious scripts that execute in the context of victim users' browsers, potentially leading to session hijacking, credential theft, or further compromise of the WordPress site.

Affected Products

• Ecover Builder For Dummies plugin for WordPress version 1.0 and earlier
• WordPress installations using the vulnerable ecover shortcode functionality

Discovery Timeline

• 2026-03-21 - CVE-2026-4077 published to NVD
• 2026-03-23 - Last updated in NVD database

Technical Details for CVE-2026-4077

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability exists within the shortcode processing functionality of the Ecover Builder For Dummies WordPress plugin. The plugin fails to properly sanitize user-supplied input in the id parameter when processing the ecover shortcode. When a user with Contributor-level privileges or higher creates or edits a post containing the malicious shortcode, the unsanitized content is stored in the database and rendered without proper output escaping to all users who view the affected page.

The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), which represents the failure to neutralize or incorrectly neutralize user-controllable input before it is placed in output used as a web page served to other users.

Root Cause

The root cause of this vulnerability lies in the plugin_builder.php file where the id shortcode attribute is processed. The plugin directly uses user-supplied values from shortcode attributes without applying WordPress's built-in sanitization functions such as esc_attr(), esc_html(), or wp_kses(). This allows specially crafted input containing JavaScript code to be stored and later rendered in the HTML output.

The vulnerable code paths have been identified in multiple locations within the plugin source, specifically around lines 39, 44, and 58 of plugin_builder.php. For technical details, see the WordPress Plugin Source Code.

Attack Vector

The attack requires network access and authenticated access with at least Contributor-level privileges on the WordPress site. An attacker would craft a malicious shortcode with JavaScript embedded in the id parameter:

The malicious shortcode would be embedded in a post or page, storing the payload persistently. When any user (including administrators) views the page containing the malicious shortcode, the injected script executes in their browser context.

This vulnerability can be exploited without user interaction once the malicious content is in place, and the impact extends beyond the attacker's own session (changed scope), potentially affecting administrator accounts and enabling further site compromise.

Detection Methods for CVE-2026-4077

Indicators of Compromise

• Unusual or suspicious content within WordPress posts containing the [ecover] shortcode
• JavaScript code or HTML event handlers present in shortcode id attributes in the database
• Unexpected script execution or browser alerts when viewing pages with ecover shortcodes
• Modified posts or pages from Contributor-level user accounts with embedded script content

Detection Strategies

• Review WordPress database for ecover shortcode entries containing suspicious patterns such as <script>, javascript:, or HTML event handlers (onerror, onload, onclick)
• Implement Web Application Firewall (WAF) rules to detect XSS patterns in POST requests to WordPress admin interfaces
• Monitor WordPress audit logs for unusual post modifications by Contributor-level users
• Use WordPress security scanning plugins to identify stored XSS payloads in post content

Monitoring Recommendations

• Enable comprehensive logging for WordPress post creation and modification activities
• Deploy SentinelOne Singularity to monitor for suspicious script injection attempts and browser-based attacks
• Implement real-time alerting for database modifications containing known XSS payload patterns
• Regularly audit user privileges to ensure Contributor access is granted only when necessary

How to Mitigate CVE-2026-4077

Immediate Actions Required

• Disable or remove the Ecover Builder For Dummies plugin until a patched version is available
• Audit existing posts and pages for any instances of the [ecover] shortcode containing suspicious content
• Review and sanitize any existing shortcode content in the WordPress database
• Restrict Contributor-level access to trusted users only

Patch Information

At the time of publication, no official patch has been released for this vulnerability. Site administrators should monitor the Wordfence Vulnerability Analysis and the WordPress plugin repository for security updates.

Workarounds

• Completely deactivate and delete the Ecover Builder For Dummies plugin from WordPress installations
• If plugin functionality is essential, implement custom input validation by modifying the plugin code to use esc_attr() on all shortcode attributes
• Deploy a Web Application Firewall with rules to block XSS payloads targeting WordPress shortcodes
• Temporarily demote or remove Contributor-level user accounts until the vulnerability is addressed

# WordPress CLI commands to identify potentially affected content
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%[ecover%' AND post_content REGEXP '<script|javascript:|on[a-z]+='"

# Deactivate the vulnerable plugin
wp plugin deactivate ecover-builder-for-dummies

# List users with Contributor role for review
wp user list --role=contributor --fields=ID,user_login,user_email