CVE-2026-15233 in Nested Pages Plugin
Summary
by MITRE • 08/04/2026
The Nested Pages WordPress plugin before 3.2.15 does not properly escape post titles before outputting them into HTML attributes on an administrative listing screen, allowing users with the Editor role (or Contributor/Author when the Nested Pages WordPress plugin before 3.2.15 is enabled for the post type) to inject arbitrary JavaScript that executes in the session of any higher-privileged user who views that screen.
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Analysis
by VulDB Data Team • 08/04/2026
The vulnerability in the Nested Pages WordPress plugin affects versions prior to 3.2.15 and represents a classic cross-site scripting flaw that exploits improper output sanitization within administrative interfaces. This issue occurs when post titles are rendered into HTML attributes on the administrative listing screen without proper escaping mechanisms, creating an environment where malicious input can be executed as JavaScript code in the context of higher-privileged user sessions.
The technical exploitation leverages the fact that the plugin fails to implement adequate HTML attribute escaping before rendering post titles into administrative interfaces. When editors or other roles with sufficient privileges create posts containing malicious JavaScript within their titles, this content gets embedded directly into HTML attributes such as onclick, onmouseover, or similar event handlers without proper sanitization. The vulnerability specifically targets the administrative listing screen where multiple posts are displayed, making it particularly dangerous since any higher-privileged user who views this screen becomes susceptible to the injected payload execution.
This security flaw allows attackers with Editor roles to execute arbitrary JavaScript code in the sessions of administrators and other privileged users, potentially leading to complete session hijacking, data exfiltration, or further exploitation within the WordPress environment. The vulnerability's impact is amplified because it requires minimal privileges to exploit - only Editor-level access or equivalent permissions for specific post types, making it particularly concerning for sites with multiple editors or contributors who may not be fully trusted. The execution context of the payload occurs within the browser session of any user who views the affected administrative listing screen, creating a persistent threat vector.
The vulnerability aligns with CWE-79 which describes Cross-Site Scripting (XSS) flaws occurring when untrusted data is output into HTML contexts without proper escaping. This particular instance represents a stored XSS vulnerability since malicious payloads are saved within post titles and executed whenever the affected page is loaded. From an ATT&CK framework perspective, this maps to T1566.001 - Phishing via Social Media and T1078 - Valid Accounts as attackers can leverage this to gain elevated privileges through session hijacking or by executing malicious scripts that collect credentials or perform unauthorized actions within the WordPress admin interface.
Organizations should immediately update to Nested Pages plugin version 3.2.15 or later to remediate this vulnerability. Additional mitigations include implementing strict content validation for post titles, employing Content Security Policy headers to limit script execution, and restricting administrative privileges to only trusted users. Regular security audits of WordPress plugins, particularly those with administrative interfaces, should be conducted to identify similar output escaping issues that could lead to similar exploitation vectors. The vulnerability demonstrates the critical importance of proper input sanitization and output escaping in all user-facing administrative interfaces where untrusted data is rendered into HTML contexts, especially within content management systems where multiple user roles exist with varying privilege levels.