CVE-2026-6171 in Bold Page Builder Plugin
Summary
by MITRE • 09/30/2026
The Bold Page Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'target' parameter of the plugin's bt_bb_icon shortcode in all versions up to, and including, 5.7.2 due to insufficient input sanitization and output escaping on user-supplied attributes. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 09/30/2026
The Bold Page Builder plugin for WordPress contains a critical security vulnerability identified as Stored Cross-Site Scripting within the bt_bb_icon shortcode's target parameter. This flaw exists across all versions up to and including 5.7.2, stemming from insufficient input sanitization and output escaping mechanisms when processing user-supplied attributes. The nature of this vulnerability allows authenticated attackers who possess Contributor-level access or higher privileges to inject arbitrary web scripts into pages managed by the plugin. Unlike reflected XSS attacks that require tricking a user into clicking a malicious link, stored vulnerabilities persist on the target server, meaning the injected script executes automatically whenever any user accesses an affected page. This persistence significantly amplifies the potential impact of the attack vector, as it does not rely solely on social engineering to achieve execution but rather leverages the inherent trust users place in legitimate website content.
From a technical perspective, the vulnerability arises because the plugin fails to properly validate or escape special characters within the target attribute before rendering them into HTML output. This lack of rigorous sanitization allows malicious JavaScript code to be embedded directly into the page structure. When a browser parses this compromised page, it interprets the injected script as legitimate content and executes it in the context of the current user session. Consequently, an attacker can exploit this execution environment to perform actions such as stealing session cookies, capturing sensitive form data, or performing unauthorized administrative actions on behalf of the victim. This aligns with CWE-79, which classifies improper neutralization of input during web page generation, and maps directly to MITRE ATT&CK technique T1059.007 for JavaScript execution within a browser environment.
The operational impact of this vulnerability is severe due to its stored nature and the relatively low privilege level required to exploit it. Contributor-level access in WordPress typically allows users to manage posts but not necessarily modify core site settings, making it an attractive entry point for attackers seeking to escalate their influence without needing full administrator credentials. Once executed, the malicious script can compromise user confidentiality by exfiltrating sensitive information such as authentication tokens or personal data stored within cookies. It also threatens integrity and availability by allowing attackers to deface pages, redirect users to phishing sites, or install additional malware payloads through drive-by downloads. The widespread use of page builder plugins means that many websites are susceptible if they have not yet applied the necessary updates, creating a broad attack surface for automated exploitation campaigns targeting WordPress ecosystems.
Mitigation strategies must focus on immediate remediation and ongoing security hygiene. Administrators should upgrade the Bold Page Builder plugin to version 5.7.3 or later as soon as possible, where these sanitization issues have been addressed by the developers. In cases where upgrading is not immediately feasible, implementing a Web Application Firewall can help filter out malicious payloads attempting to exploit this specific parameter before they reach the application logic. Additionally, enforcing strict Content Security Policy headers can mitigate the impact of successful XSS attacks by restricting the sources from which scripts are allowed to execute. Regular security audits and code reviews focusing on input validation and output encoding practices are essential for preventing similar vulnerabilities in custom or third-party WordPress extensions. Maintaining up-to-date software components remains the most effective defense against such persistent threats.