CVE-2026-1231: Beaver Builder WordPress XSS Vulnerability

CVE-2026-1231 Overview

A Stored Cross-Site Scripting (XSS) vulnerability has been identified in the Beaver Builder Page Builder – Drag and Drop Website Builder plugin for WordPress. The vulnerability exists in the js Global Settings parameter due to missing capability checks on the save_global_settings() function combined with insufficient input sanitization and output escaping. This allows authenticated attackers with Custom-level access or above who have been granted Beaver Builder access to inject arbitrary web scripts into pages that execute whenever a user accesses an injected page.

Critical Impact

Authenticated attackers can inject persistent malicious JavaScript that executes in the context of any user visiting compromised pages, potentially leading to session hijacking, credential theft, or further attacks against site administrators.

Affected Products

• Beaver Builder Page Builder – Drag and Drop Website Builder plugin for WordPress versions up to and including 2.10.0.5
• Beaver Builder Lite Version (WordPress.org hosted)

Discovery Timeline

• February 11, 2026 - CVE-2026-1231 published to NVD
• February 11, 2026 - Last updated in NVD database

Technical Details for CVE-2026-1231

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability stems from a combination of two security weaknesses in the Beaver Builder plugin. First, the save_global_settings() function lacks proper capability checks, allowing users with lower privilege levels than intended to modify global settings. Second, the js parameter within Global Settings does not undergo adequate input sanitization before being stored, nor is it properly escaped when output to the page.

When an attacker with Beaver Builder access injects malicious JavaScript code into the js Global Settings field, that code is stored in the WordPress database. Subsequently, whenever any user visits a page where these global settings are rendered, the malicious script executes in their browser context. This persistent nature makes the vulnerability particularly dangerous as it can affect all site visitors and administrators.

The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), which covers cross-site scripting weaknesses.

Root Cause

The root cause of this vulnerability lies in two distinct implementation failures within the Beaver Builder plugin:

1. Missing Capability Checks: The save_global_settings() function in class-fl-builder-ajax.php does not properly verify that the requesting user has appropriate administrative capabilities before allowing modifications to global settings.

2. Insufficient Input Validation: User-supplied input to the js Global Settings parameter is not sanitized to remove or encode potentially dangerous characters and script content before being stored in the database or rendered on pages.

Attack Vector

The attack requires network access and authenticated access to a WordPress installation where the attacker has been granted Beaver Builder plugin access at the Custom level or above. The attack flow proceeds as follows:

1. The attacker authenticates to the WordPress site with an account that has Beaver Builder access
2. The attacker navigates to the Global Settings interface within Beaver Builder
3. The attacker injects malicious JavaScript code into the js parameter field
4. The malicious payload is stored without proper sanitization due to missing capability checks
5. When any user (including administrators) visits a page rendered by Beaver Builder, the injected script executes in their browser
6. The attacker can steal session cookies, capture credentials, redirect users, or perform actions on behalf of the victim

The vulnerability affects pages across the scope of the application, meaning scripts injected through this vector can impact users on other pages where the global settings are loaded.

Detection Methods for CVE-2026-1231

Indicators of Compromise

• Unexpected JavaScript code present in Beaver Builder Global Settings, particularly in the js parameter
• Suspicious modifications to the fl_builder_global_settings option in the WordPress database
• Unexplained user session activity or unauthorized administrative actions
• Reports from users about unexpected browser behavior, redirects, or pop-ups on Beaver Builder pages

Detection Strategies

• Monitor WordPress audit logs for changes to Beaver Builder Global Settings by non-administrator users
• Implement Content Security Policy (CSP) headers to detect and block unauthorized inline script execution
• Review stored Global Settings periodically for suspicious JavaScript content
• Use Web Application Firewalls (WAF) configured to detect XSS patterns in POST requests to Beaver Builder AJAX endpoints

Monitoring Recommendations

• Enable detailed logging for WordPress AJAX actions, particularly those related to Beaver Builder settings changes
• Configure alerts for modifications to the wp_options table entries associated with Beaver Builder
• Monitor browser console errors across the site that may indicate blocked or failing malicious scripts
• Implement real-time alerting for CSP violations that may indicate XSS exploitation attempts

How to Mitigate CVE-2026-1231

Immediate Actions Required

• Update Beaver Builder Page Builder plugin to a version newer than 2.10.0.5 immediately when a patch becomes available
• Audit existing Beaver Builder Global Settings for any suspicious JavaScript content
• Review user accounts with Beaver Builder access and remove unnecessary permissions
• Implement strict Content Security Policy headers to mitigate the impact of any stored XSS payloads

Patch Information

Organizations using Beaver Builder should monitor the Wordfence Vulnerability Analysis for patch availability and update information. Technical details about the affected code can be reviewed in the WordPress plugin repository:

• WordPress Beaver Builder Ajax Code
• WordPress Beaver Builder Model Code
• WordPress Beaver Builder Main Code

Workarounds

• Restrict Beaver Builder access to only trusted administrator accounts until a patch is available
• Implement Web Application Firewall rules to filter malicious JavaScript patterns in requests to Beaver Builder endpoints
• Add Content Security Policy headers that restrict script execution to trusted sources
• Consider temporarily disabling the Global Settings JavaScript functionality if not required for site operation

# Example Content Security Policy header configuration for Apache
# Add to .htaccess to help mitigate XSS impact
Header set Content-Security-Policy "script-src 'self' 'unsafe-inline' trusted-cdn.example.com; object-src 'none';"

# For Nginx, add to server block
# add_header Content-Security-Policy "script-src 'self' 'unsafe-inline' trusted-cdn.example.com; object-src 'none';";