CVE-2024-4041 in Yoast SEO Plugin
Summary
by MITRE • 05/14/2024
The Yoast SEO plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via URLs in all versions up to, and including, 22.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 05/08/2026
The Yoast SEO plugin for WordPress represents one of the most widely used SEO tools in the WordPress ecosystem, with over 100 million downloads across all versions. This plugin provides essential search engine optimization features including meta tag management, XML sitemap generation, and content analysis tools. The vulnerability affects all versions up to and including 22.5, making it a critical concern for millions of WordPress sites that rely on this plugin for their SEO infrastructure. The reflected cross-site scripting vulnerability stems from inadequate input sanitization mechanisms within the plugin's URL handling processes, specifically failing to properly escape output before rendering user-supplied data in web responses.
This vulnerability operates through a classic reflected XSS attack vector where malicious scripts are injected into URLs and subsequently executed when users navigate to affected pages. The flaw occurs because the plugin fails to sanitize user input parameters before incorporating them into HTML output, creating an environment where attacker-controlled data can be rendered as executable code within the user's browser context. The vulnerability is particularly dangerous because it requires no authentication, allowing attackers to exploit it through social engineering techniques such as phishing emails or compromised websites that direct users to malicious URLs containing crafted payloads. The reflected nature of the vulnerability means that the malicious script is not stored on the server but rather reflected back to the user through the server's response, making it difficult to detect through traditional security scanning methods.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities including session hijacking, credential theft, and redirection to malicious websites. According to the CWE database, this vulnerability maps to CWE-79 which specifically addresses improper neutralization of input during web page generation, and aligns with ATT&CK technique T1566 which describes social engineering tactics used to gain initial access. The vulnerability affects not just individual users but entire WordPress installations, as the Yoast plugin is integrated into core WordPress functionality and often used across multiple sites within the same organization. Attackers can craft malicious URLs that appear legitimate, potentially leading to widespread compromise of WordPress sites that have not yet patched this vulnerability.
Mitigation strategies should focus on immediate patching to version 22.6 or later, which contains the necessary input sanitization fixes. Organizations should also implement additional security measures including web application firewalls, input validation rules, and monitoring for suspicious URL patterns. The vulnerability demonstrates the critical importance of proper output escaping and input validation in web applications, particularly those handling user-supplied data in URL parameters. Security teams should conduct comprehensive audits of all WordPress plugins and themes to identify similar vulnerabilities, as this flaw represents a common pattern in web application security where insufficient sanitization creates dangerous attack surfaces. Regular security updates and patch management processes become essential components of WordPress security hygiene, as this vulnerability affects such a widely deployed plugin that many sites may remain unpatched for extended periods. The incident underscores the necessity of implementing automated security monitoring and the importance of maintaining up-to-date security practices across all web application components.