CVE-2025-26991: WPPizza Reflected XSS Vulnerability

CVE-2025-26991 Overview

A Reflected Cross-Site Scripting (XSS) vulnerability has been identified in the WPPizza WordPress plugin developed by ollybach. This vulnerability allows attackers to inject malicious scripts into web pages viewed by users of affected WordPress installations. The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation).

Reflected XSS vulnerabilities occur when user-supplied input is immediately returned by the application without proper sanitization, enabling attackers to craft malicious URLs that execute arbitrary JavaScript in the context of the victim's browser session.

Critical Impact

Attackers can exploit this vulnerability to steal session cookies, redirect users to malicious sites, perform actions on behalf of authenticated users, or deface web pages on affected WordPress installations running WPPizza plugin version 3.19.4 or earlier.

Affected Products

• WPPizza WordPress Plugin versions up to and including 3.19.4
• WordPress installations using vulnerable WPPizza plugin versions

Discovery Timeline

• 2025-02-25 - CVE-2025-26991 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-26991

Vulnerability Analysis

The WPPizza plugin fails to properly sanitize user-controlled input before reflecting it back in the rendered HTML output. This Reflected XSS vulnerability allows an attacker to inject malicious JavaScript code through specially crafted HTTP requests. When a victim clicks on a malicious link or visits a compromised page, the injected script executes in their browser within the security context of the vulnerable WordPress site.

The impact of successful exploitation includes the ability to hijack user sessions, modify page content, redirect users to phishing sites, or perform any action the authenticated user is authorized to perform on the WordPress installation.

Root Cause

The root cause of CVE-2025-26991 is improper neutralization of user input during web page generation. The WPPizza plugin processes user-supplied data without adequate input validation or output encoding, allowing malicious HTML and JavaScript content to be reflected in the response and executed by the victim's browser.

Attack Vector

The attack requires social engineering to trick a victim into clicking a malicious URL or visiting a page containing the crafted payload. The attacker constructs a URL with embedded JavaScript code targeting a vulnerable parameter in the WPPizza plugin. When the victim accesses this URL while authenticated to the WordPress site, the malicious script executes with the victim's session privileges.

The vulnerability manifests when user input is reflected directly into the HTML response without proper encoding or sanitization. For detailed technical information, refer to the Patchstack security advisory.

Detection Methods for CVE-2025-26991

Indicators of Compromise

• Unusual URL parameters containing JavaScript code or HTML tags in requests to WPPizza plugin endpoints
• Access logs showing requests with encoded <script> tags, event handlers like onerror, onload, or onclick, or javascript: protocol handlers
• Reports from users about unexpected redirects or browser behavior when interacting with pizza ordering functionality
• Web Application Firewall alerts for XSS attack patterns targeting WordPress plugin endpoints

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common XSS payloads in URL parameters and form submissions
• Enable WordPress security logging to capture suspicious requests targeting plugin endpoints
• Deploy browser-based Content Security Policy (CSP) headers to mitigate script injection attacks
• Use automated vulnerability scanning tools to identify unpatched WPPizza installations

Monitoring Recommendations

• Monitor HTTP access logs for requests containing suspicious patterns such as <script>, javascript:, or URL-encoded equivalents
• Set up alerts for unusual traffic patterns to WPPizza plugin endpoints
• Review security plugin logs for blocked XSS attempts
• Track plugin version inventory across WordPress installations to identify unpatched instances

How to Mitigate CVE-2025-26991

Immediate Actions Required

• Update the WPPizza plugin to the latest patched version immediately
• Implement a Web Application Firewall with XSS protection rules as an interim measure
• Review WordPress access logs for evidence of exploitation attempts
• Enable Content Security Policy headers to restrict inline script execution

Patch Information

Update the WPPizza plugin to a version newer than 3.19.4 that addresses the Reflected XSS vulnerability. Plugin updates can be applied through the WordPress admin dashboard under Plugins > Installed Plugins, or by downloading the latest version from the WordPress plugin repository. Always backup your WordPress installation before applying updates.

For additional details, see the Patchstack vulnerability database entry.

Workarounds

• Deploy a Web Application Firewall (WAF) with XSS filtering capabilities to block malicious requests until patching is possible
• Implement Content Security Policy (CSP) headers to prevent inline script execution
• Temporarily disable the WPPizza plugin if it is not critical to site operations
• Restrict access to WordPress admin areas to trusted IP addresses only

# Example Apache .htaccess CSP header configuration
<IfModule mod_headers.c>
    Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline';"
</IfModule>