CVE-2025-31738: LeadQuizzes WordPress Plugin XSS Vulnerability

CVE-2025-31738 Overview

CVE-2025-31738 is a stored Cross-Site Scripting (XSS) vulnerability in the LeadQuizzes WordPress plugin developed by yazamodeveloper. The flaw affects all versions of LeadQuizzes up to and including 1.1.0. It stems from improper neutralization of user-supplied input during web page generation, tracked as [CWE-79]. An authenticated attacker with low privileges can inject malicious JavaScript that persists in the application and executes in the browsers of other users who view the affected content. Successful exploitation requires user interaction and can lead to session compromise, credential theft, and unauthorized actions performed under a victim's context.

Critical Impact
Authenticated attackers can inject persistent JavaScript into LeadQuizzes content, enabling browser-based attacks against administrators and site visitors with a scope change to other components.

Affected Products

yazamodeveloper LeadQuizzes WordPress plugin
All versions from n/a through 1.1.0
WordPress sites running the vulnerable LeadQuizzes plugin

Discovery Timeline

2025-04-01 - CVE-2025-31738 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31738

Vulnerability Analysis

The LeadQuizzes plugin fails to properly sanitize and encode user-controlled input before rendering it within generated web pages. When an authenticated user submits crafted input containing HTML or JavaScript payloads through a vulnerable plugin field, the input is stored in the WordPress database. Any subsequent page load that renders the stored content executes the attacker-supplied script in the visitor's browser session.

Because the vulnerability is stored rather than reflected, exploitation persists across sessions and affects every user who accesses the compromised page. The changed scope indicates that injected script can access resources beyond the vulnerable component, including cookies and session data from the broader WordPress site.

Root Cause

The root cause is missing or insufficient output encoding when the plugin renders user-controlled data in HTML contexts. The plugin does not apply WordPress escaping functions such as esc_html(), esc_attr(), or wp_kses() to input before echoing it into page markup, allowing raw HTML and <script> payloads to be interpreted by the browser.

Attack Vector

Exploitation requires network access to the WordPress site and authenticated access with low-level privileges, along with interaction from a victim user who must load the page containing the injected payload. An attacker submits a payload through a LeadQuizzes input field that lacks server-side sanitization. When an administrator or other user views the affected quiz or content page, the script executes with the victim's session context. Consult the Patchstack Vulnerability Report for additional technical detail.

Detection Methods for CVE-2025-31738

Indicators of Compromise

Unexpected <script> tags, event handlers, or javascript: URIs stored in LeadQuizzes-related database tables or post metadata
Outbound HTTP requests from visitor browsers to unknown external domains after loading quiz pages
Unauthorized administrative actions or new WordPress user accounts created following administrator visits to quiz pages
Anomalous cookie exfiltration patterns in web server or CDN logs

Detection Strategies

Audit the WordPress wp_posts and wp_postmeta tables for HTML or JavaScript content associated with LeadQuizzes entries
Deploy a Web Application Firewall (WAF) rule set to identify XSS payload patterns in POST requests to plugin endpoints
Enforce a strict Content Security Policy (CSP) and monitor CSP violation reports for inline script execution
Review WordPress audit logs for content edits made by low-privilege accounts to quiz assets

Monitoring Recommendations

Alert on modifications to LeadQuizzes content by non-administrator accounts
Monitor administrator sessions for anomalous browser-originated API calls following quiz page views
Track newly created privileged WordPress accounts and REST API activity from unusual sources

How to Mitigate CVE-2025-31738

Immediate Actions Required

Identify all WordPress installations running LeadQuizzes version 1.1.0 or earlier
Deactivate the LeadQuizzes plugin until a patched version is available and installed
Rotate WordPress administrator credentials and invalidate active sessions if compromise is suspected
Review stored quiz content and remove any embedded scripts or suspicious HTML

Patch Information

At the time of the latest NVD update, the advisory lists affected versions from n/a through 1.1.0 and does not identify a fixed release. Monitor the Patchstack Vulnerability Report and the plugin vendor for a patched release, and apply updates immediately upon availability.

Workarounds

Deactivate and remove the LeadQuizzes plugin until a fixed version is released
Restrict low-privilege accounts from accessing plugin editing capabilities using role management controls
Deploy WAF rules that block XSS payload patterns targeting the plugin's input endpoints
Enforce a strict Content Security Policy that disallows inline scripts and untrusted origins

bash

# Example: disable the LeadQuizzes plugin using WP-CLI
wp plugin deactivate leadquizzes
wp plugin delete leadquizzes

# Example: add a restrictive Content Security Policy header in .htaccess
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'"