Vulnerability · Published Apr 14, 2026 · Assigned by GitHub_M
CVE-2026-34602Chamilo LMS: IDOR in /api/course_rel_users Allows Unauthorized Enrollment of Arbitrary Users into Courses
High 7.1
In plain English
A high-severity authorization bypass via user-controlled key in chamilo-lms from chamilo. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities).
Official description
Chamilo LMS is an open-source learning management system. In versions prior to 2.0.0-RC.3, the /api/course_rel_users endpoint is vulnerable to Insecure Direct Object Reference (IDOR), allowing an authenticated attacker to modify the user parameter in the request body to enroll any arbitrary user into any course without proper authorization checks. The backend trusts the user-supplied input for the user field and performs no server-side verification that the requester owns the referenced user ID or has permission to act on behalf of other users. This enables unauthorized manipulation of user-course relationships, potentially granting unintended access to course materials, bypassing enrollment controls, and compromising platform integrity. This issue has been fixed in version 2.0.0-RC.3.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| chamilo | chamilo-lms | < 2.0.0-RC.3 |
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
References
- https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-x373-8j9j-g5pj x_refsource_CONFIRM
- https://github.com/chamilo/chamilo-lms/commit/2a9f060fa9d50fc9a92ed93af774d2619642df92 x_refsource_MISC
- https://github.com/chamilo/chamilo-lms/commit/bd2ba34c2e74475587e38c74c90c2934e69c8779 x_refsource_MISC
- https://github.com/chamilo/chamilo-lms/commit/c9c30cdc48afae57cd6ab012ae2eceafd351a40e x_refsource_MISC
- https://github.com/chamilo/chamilo-lms/releases/tag/v2.0.0-RC.3 x_refsource_MISC