CVE-2026-85569 in Tutor LMS Plugin
Summary
by MITRE • 09/16/2026
The Tutor LMS WordPress plugin before 4.0.8 does not correctly determine whether an incoming request is addressed to its own REST API, and does not enforce the permission recorded against an API credential, allowing the holder of a read-only key to act as the administrator account that issued it.
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Analysis
by VulDB Data Team • 09/16/2026
The vulnerability identified in Tutor LMS versions prior to 4.0.8 represents a critical failure in access control logic within the plugin's REST API implementation. This flaw stems from an insufficient validation mechanism when processing incoming HTTP requests directed at specific endpoints managed by the plugin. The core issue lies in how the application determines whether a request is legitimately addressed to its own internal APIs and, more critically, how it validates the permissions associated with the authentication credentials provided during that request. In secure systems, REST API keys or tokens are typically bound to specific scopes of authority, such as read-only access for viewing content without modification capabilities. However, in this instance, the plugin fails to correctly map these granular permission sets to the actions being performed by the authenticated user context.
From a technical perspective, the flaw allows an attacker possessing only a read-only API key to escalate their privileges effectively bypassing intended restrictions. When such a request is processed, the application does not strictly enforce the limitations recorded against that specific credential. Instead, it appears to default to or inherit higher-level permissions associated with the administrator account that originally generated the API key. This behavior violates the principle of least privilege, which dictates that users and systems should operate with only the minimum levels of access necessary for their intended functions. By failing to isolate the scope of the read-only token from the administrative capabilities of its issuer, the system creates a pathway for unauthorized modification or deletion of data that should remain protected under standard user roles.
The operational impact of this vulnerability is severe, particularly in multi-author WordPress environments where different users may have varying levels of trust and access rights. An attacker who has obtained read-only API credentials could exploit this flaw to perform administrative actions such as creating new administrator accounts, modifying site settings, installing malicious plugins, or altering course content within the LMS platform. This effectively compromises the integrity and confidentiality of the entire WordPress installation managed by Tutor LMS. Since REST APIs are often exposed publicly for integration with third-party applications, the attack surface is broadened significantly compared to traditional login forms that might be protected by additional layers like CAPTCHA or rate limiting. The ability to act as an administrator means complete control over the website's backend functions can be achieved remotely without needing valid administrative credentials directly.
This vulnerability aligns closely with CWE-269, which describes Improper Privilege Assignment, where a user is granted more privileges than they should have based on their role or authentication token scope. Furthermore, in terms of the MITRE ATT&CK framework for enterprise security, this behavior facilitates privilege escalation and can be categorized under techniques related to API abuse and unauthorized access. Attackers often leverage such flaws during post-exploitation phases to maintain persistence or expand their foothold within a compromised network by gaining higher-level system control through seemingly benign API interactions.
Mitigation strategies must focus on immediate patching and rigorous validation of request contexts. The primary remediation is to upgrade the Tutor LMS plugin to version 4.0.8 or later, where this logic error has been corrected to properly enforce permission scopes associated with each API key. For organizations unable to update immediately due to compatibility constraints, temporary mitigations should include restricting access to REST endpoints via web application firewalls by validating request origins and ensuring that only necessary APIs are exposed publicly. Additionally, implementing strict rate limiting on authentication-related requests can help mitigate brute-force attempts aimed at discovering valid API keys. Regular audits of plugin code for similar privilege escalation flaws in other WordPress extensions are also recommended to maintain a robust security posture against evolving threats targeting RESTful interfaces.