CVE-2024-43926: Beaver Builder Reflected XSS Vulnerability

CVE-2024-43926 Overview

CVE-2024-43926 is a reflected cross-site scripting (XSS) vulnerability in the Beaver Builder plugin for WordPress, developed by The Beaver Builder Team (Fastlinemedia). The flaw stems from improper neutralization of user-supplied input during web page generation [CWE-79]. Attackers can craft malicious URLs that execute arbitrary JavaScript in a victim's browser when the victim clicks the link. The issue affects all Beaver Builder versions up to and including 2.8.3.2. Exploitation requires user interaction but no authentication, and the scope is changed, meaning the injected script can affect resources beyond the vulnerable component.

Critical Impact
Attackers can execute arbitrary JavaScript in an authenticated user's session, enabling session theft, credential harvesting, and administrative actions on affected WordPress sites.

Affected Products

Beaver Builder Lite plugin for WordPress
All versions from n/a through 2.8.3.2
WordPress sites running the vulnerable plugin

Discovery Timeline

2024-08-29 - CVE-2024-43926 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-43926

Vulnerability Analysis

The vulnerability is a reflected XSS flaw [CWE-79] in the Beaver Builder WordPress page builder plugin. Reflected XSS occurs when an application accepts user input through a request parameter and includes that input in the HTTP response without proper sanitization or output encoding. An attacker constructs a URL containing a malicious script payload and delivers it to a target through phishing, social engineering, or malicious links. When the victim's browser renders the response, the injected script executes within the context of the vulnerable site.

The attack requires user interaction and operates across a security scope boundary, which allows the injected script to impact resources beyond the plugin itself. This includes the broader WordPress session context.

Root Cause

The root cause is improper neutralization of input during web page generation. The plugin reflects request parameters into HTML output without sufficient encoding or validation. This permits attacker-controlled content to be interpreted as executable JavaScript by the victim's browser.

Attack Vector

Exploitation is network-based and requires no authentication. An attacker crafts a URL that includes a JavaScript payload in a parameter processed by the Beaver Builder plugin. The attacker then delivers the URL to a victim, typically a logged-in WordPress administrator. When the victim clicks the link, the malicious script executes in their browser session, potentially stealing cookies, performing actions on behalf of the user, or redirecting to attacker-controlled infrastructure. See the Patchstack XSS Vulnerability Advisory for additional technical details.

Detection Methods for CVE-2024-43926

Indicators of Compromise

Suspicious URL requests containing script tags, event handlers, or encoded JavaScript targeting Beaver Builder endpoints
Unexpected outbound requests from WordPress administrator browsers to unknown domains following link clicks
Unauthorized administrative actions in WordPress audit logs that correlate with external referrers

Detection Strategies

Inspect web server access logs for requests containing XSS payload patterns such as <script>, javascript:, onerror=, or URL-encoded equivalents targeting Beaver Builder parameters
Deploy a web application firewall (WAF) with signatures for reflected XSS payloads on /wp-content/plugins/beaver-builder-* paths
Monitor the WordPress plugin version against the vulnerable range (through 2.8.3.2) using asset inventory tooling

Monitoring Recommendations

Enable Content Security Policy (CSP) reporting to capture inline script execution attempts
Track administrator session activity for anomalous requests originating from external referrers
Alert on WordPress configuration changes, user creation events, or plugin modifications outside maintenance windows

How to Mitigate CVE-2024-43926

Immediate Actions Required

Update the Beaver Builder plugin to a version later than 2.8.3.2 as soon as a patched release is available
Audit WordPress administrator accounts for unauthorized changes, newly created users, or modified plugin files
Instruct administrators to avoid clicking untrusted links while authenticated to the WordPress admin panel

Patch Information

The vulnerability affects Beaver Builder versions up to and including 2.8.3.2. Site operators should consult the Patchstack XSS Vulnerability Advisory and the Beaver Builder vendor site for the latest fixed release and apply it through the WordPress plugin manager.

Workarounds

Deploy a WAF with rules that block reflected XSS payloads targeting WordPress plugin endpoints
Enforce a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins
Temporarily disable the Beaver Builder plugin on sites that cannot be patched immediately

bash

# Example WordPress CLI commands to check and update the plugin
wp plugin get beaver-builder-lite-version --field=version
wp plugin update beaver-builder-lite-version