CVE-2026-111407 in Tutor LMS Plugin
Summary
by MITRE • 10/19/2026
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Themeum Tutor LMS tutor allows Stored XSS.This issue affects Tutor LMS: from n/a through 4.1.2.
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Analysis
by VulDB Data Team • 10/19/2026
The identified security flaw represents a classic instance of Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting or XSS. Specifically, this vulnerability manifests as a Stored XSS within the Themeum Tutor LMS plugin for WordPress. Unlike reflected XSS attacks where malicious scripts are executed immediately via a crafted link, stored vulnerabilities persist on the target server. In this context, an attacker can inject malicious JavaScript code into input fields that are subsequently saved to the database without proper sanitization or validation. When other users or administrators later view the affected content within the Tutor LMS interface, the browser executes the embedded script in the security context of the vulnerable application. This persistence mechanism significantly increases the severity and potential impact of the vulnerability compared to transient attacks, as the malicious payload remains active until manually removed from the database or the plugin is updated.
The technical root cause lies in the insufficient filtering of user-supplied data before it is rendered back into HTML output by the Tutor LMS application. The software fails to properly neutralize special characters that have semantic meaning within HTML and JavaScript, such as angle brackets, quotes, and ampersands. This oversight allows an attacker to break out of the expected context of a text field or form input and inject executable script tags. Because this occurs in a WordPress environment running Tutor LMS versions from n/a through 4.1.2, any user with the ability to create content that is displayed elsewhere on the site can exploit this flaw. This typically includes roles such as Instructors who manage course materials, quizzes, or discussions, depending on the specific input vector within the plugin's architecture. The lack of output encoding ensures that the browser interprets the injected code as legitimate application logic rather than data.
The operational impact of a successful Stored XSS attack in this scenario is severe and multifaceted. An attacker can steal session cookies, which may lead to account takeover if secure cookie flags are not properly configured or if the victim uses persistent sessions. Beyond credential theft, the vulnerability allows for complete compromise of the user's interaction with the platform. Attackers can perform actions on behalf of the victim, such as modifying course settings, enrolling students in unauthorized courses, deleting content, or altering grades. Furthermore, the malicious script can be used to deface the website by injecting misleading HTML elements or redirecting users to phishing sites designed to harvest credentials from unsuspecting visitors. In enterprise or educational environments where Tutor LMS is deployed, this could lead to significant reputational damage and loss of trust among students and staff.
From a classification perspective, this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The specific variant here involves stored persistence, which often correlates with the MITRE ATT&CK technique T1059.007: JavaScript. This tactic is frequently used in web application attacks to achieve initial access or maintain persistence within a compromised system. Security professionals should recognize that while XSS does not directly compromise server-side infrastructure like SQL injection might, it poses a critical risk to the confidentiality and integrity of user data and session management mechanisms.
To mitigate this vulnerability, immediate action is required by updating the Tutor LMS plugin to version 4.1.3 or later, where the input validation and output encoding issues have been addressed. Administrators should ensure that all instances of the software are patched promptly across their WordPress installations. In addition to applying patches, organizations should implement a Web Application Firewall (WAF) configured with rulesets capable of detecting and blocking common XSS payloads in HTTP requests. This provides an additional layer of defense against exploitation attempts while patching is being deployed. Furthermore, developers must adhere to secure coding practices that emphasize strict input validation on the server side and context-aware output encoding when rendering data into HTML, JavaScript, or CSS contexts. Regular security audits and penetration testing focused on web application vulnerabilities are recommended to identify similar flaws in other components of the learning management system infrastructure.