CVE-2026-111369 in ClassroomIO
Summary
by MITRE • 10/16/2026
ClassroomIO through 1.0.0 contains an incorrect authorization vulnerability in the PUT and DELETE /:lessonId lesson routes that allows any course member, including students, to modify lessons. Authenticated students can supply arbitrary lesson ids to change titles and stored HTML content or delete lessons in their course and in other courses and organizations.
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Analysis
by VulDB Data Team • 10/16/2026
The identified vulnerability within ClassroomIO versions up to 1.0.0 represents a critical failure in access control mechanisms, specifically categorized under CWE-284 Improper Access Control. This flaw manifests through the PUT and DELETE HTTP methods applied to lesson endpoints defined by the pattern /:lessonId. The core technical deficiency lies in the application's inability to verify whether the authenticated user initiating these requests possesses administrative privileges or ownership rights over the specific resource identified by the provided lesson ID. Instead of enforcing strict role-based access control that restricts modification and deletion operations to course administrators, instructors, or system owners, the backend logic accepts any valid authentication token from a member of the associated course context. This design oversight effectively bypasses intended security boundaries, allowing lower-privilege entities such as students to perform actions reserved for higher-privileged roles.
From an operational perspective, this vulnerability enables significant unauthorized data manipulation and destruction. An authenticated student can exploit this flaw by supplying arbitrary lesson identifiers that do not belong to their current course or even their organization. By doing so, the attacker gains the ability to alter the titles of lessons across multiple courses and organizations, leading to potential misinformation or disruption of educational content integrity. Furthermore, the DELETE capability allows for the permanent removal of lessons from other users' courses, resulting in a denial of service against specific learning materials and compromising the availability aspect of the CIA triad. The scope of impact extends beyond individual course boundaries because the lack of proper authorization checks permits cross-course and cross-organization attacks, amplifying the severity of the breach.
This type of vulnerability aligns with several entries in the MITRE ATT&CK framework, particularly those related to Privilege Escalation and Defense Evasion techniques where attackers leverage improper access controls to gain unauthorized influence over system resources. The ability to modify stored HTML content also introduces secondary risks such as Cross-Site Scripting if the application fails to sanitize input properly before storage or retrieval, although the primary issue here is the authorization bypass itself. Attackers can use this vector to deface course materials, inject malicious scripts into lesson descriptions, or simply delete critical educational assets to disrupt academic operations.
Mitigation strategies must focus on implementing robust server-side validation for all state-changing requests. Developers should enforce strict ownership verification by ensuring that only users with explicit administrative roles or direct ownership of the resource can execute PUT and DELETE operations on specific lesson IDs. This involves checking the user's role against a whitelist of allowed permissions before processing any modification request. Additionally, integrating comprehensive logging and monitoring systems will help detect anomalous patterns of access attempts from student accounts targeting resources outside their immediate scope. Regular security audits focusing on authorization logic are essential to prevent similar flaws in other endpoints within the application architecture.