CVE-2026-19573 in Affiliate Super Assistent Plugin
Summary
by MITRE • 09/01/2026
The Affiliate Super Assistent plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘doCommentShortcode’ function in all versions up to, and including, 1.10.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers 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 • 09/01/2026
The Affiliate Super Assistant plugin for WordPress contains a critical security flaw affecting all versions up to and including 1.10.2, characterized by insufficient input sanitization and output escaping within the doCommentShortcode function. This vulnerability allows unauthenticated attackers to inject arbitrary web scripts into pages managed by the application. The core technical issue stems from the failure of the plugin to properly validate user-supplied data before processing it as part of a shortcode execution context. When a comment is submitted, the system fails to strip or encode potentially malicious content, leaving the input stream vulnerable to injection attacks that can persist within the database and subsequently render in web pages viewed by other users.
This specific flaw represents a classic Stored Cross-Site Scripting vulnerability, which corresponds directly with CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). Unlike reflected XSS where malicious scripts are executed immediately within the context of an HTTP request, stored vulnerabilities persist on the target server. In this scenario, the injected script is saved as part of the comment data structure. Consequently, every time a legitimate user loads a page containing the compromised shortcode and associated comment payload, their browser executes the attacker-controlled JavaScript code in the security context of the vulnerable website. This persistence mechanism significantly amplifies the risk profile compared to transient injection vectors because the attack does not require social engineering tricks like phishing links for each execution; it relies solely on users visiting the affected page.
The operational impact of this vulnerability is severe, as it enables attackers to perform a wide range of malicious activities against end-users who interact with the infected pages. These activities can include session hijacking through the theft of authentication cookies or tokens, credential harvesting by displaying fake login forms that mimic legitimate WordPress interfaces, and defacement of website content. Furthermore, because the script executes in the context of the trusted domain, attackers can bypass same-origin policy restrictions to access sensitive data stored locally within the user's browser or initiate actions on behalf of authenticated users if they are logged into other services via single sign-on mechanisms. This effectively compromises the confidentiality and integrity of both the website administrators and its visitor base.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK technique T1059.007: Command and Scripting Interpreter::JavaScript, specifically in the context of client-side code execution for malicious purposes such as data exfiltration or further lateral movement within an organization if internal users are targeted. The lack of proper encoding means that standard HTML entities are not converted to their safe representations, allowing raw script tags to be interpreted by modern web browsers without obstruction. This is a fundamental failure in the principle of least privilege and secure coding practices regarding user input handling.
To mitigate this vulnerability, immediate action must be taken by site administrators using versions 1.10.2 or earlier of the Affiliate Super Assistant plugin. The primary remediation step is to update the plugin to the latest patched version where the developers have implemented robust sanitization filters and output escaping mechanisms for all user inputs processed through the doCommentShortcode function. Administrators should ensure that input validation functions such as wp_kses_post are applied to strip dangerous HTML tags and attributes before storage, while output escaping using functions like esc_html or esc_attr ensures that data is safely rendered in the browser context. Until an update can be deployed, temporary mitigations may include disabling comments on affected pages if feasible or implementing a Web Application Firewall rule set designed to detect and block common XSS payloads within comment submission requests. Regular security audits and adherence to OWASP guidelines for input validation are essential to prevent similar vulnerabilities from being introduced in future updates.