CVE-2025-8427 is a stored Cross-Site Scripting vulnerability identified in the Beaver Builder Plugin (Starter Version) for WordPress, affecting all versions up to and including 2.9.2.1. The vulnerability stems from improper neutralization of input during web page generation, specifically via the ‘auto_play’ parameter. Authenticated attackers with Contributor-level privileges or higher can inject malicious JavaScript code that is stored persistently within the website’s content. When other users access the compromised pages, the injected scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability does not require user interaction beyond visiting the infected page, and the attacker only needs low-level authenticated access, which is commonly granted in collaborative content management environments. The CVSS 3.1 base score of 6.4 reflects a medium severity, with an attack vector over the network, low attack complexity, and privileges required but no user interaction. No patches or known exploits are currently reported, but the risk remains significant due to the widespread use of WordPress and Beaver Builder. The vulnerability is classified under CWE-79, indicating improper input sanitization and output escaping during dynamic content generation. This flaw can undermine the confidentiality and integrity of affected websites and their users.

For European organizations, this vulnerability can lead to unauthorized script execution within trusted websites, compromising user sessions and potentially exposing sensitive data such as login credentials or personal information. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR breaches), and facilitate further attacks like phishing or malware distribution. Organizations relying on WordPress sites with collaborative content creation workflows are particularly at risk, as Contributor-level access is often granted to multiple users. The persistent nature of the stored XSS increases the attack surface, affecting all visitors to the compromised pages. This can disrupt business operations, erode customer trust, and incur remediation costs. Given the medium severity, the threat is significant but not immediately critical; however, exploitation could escalate if combined with other vulnerabilities or social engineering tactics.

1. Monitor for official patches or updates from The Beaver Builder Team and apply them promptly once available. 2. Until patches are released, restrict Contributor-level access to trusted users only, minimizing the risk of malicious input. 3. Implement additional input validation and sanitization on the ‘auto_play’ parameter at the web application firewall (WAF) or reverse proxy level to block suspicious payloads. 4. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. 5. Conduct regular security audits and code reviews of customizations involving Beaver Builder to detect and remediate unsafe input handling. 6. Educate content contributors about the risks of injecting untrusted content and enforce strict content moderation policies. 7. Use security plugins that detect and block XSS attempts and monitor logs for unusual activity related to the ‘auto_play’ parameter. 8. Backup website data regularly to enable quick restoration if compromise occurs.