Title: Chamilo LMS de Chamilo, Description: Chamilo LMS es un sistema de gestión de aprendizaje de código abierto. En versiones anteriores a la 2.0.0-RC.3, el endpoint /API/course_rel_users es vulnerable a la Referencia Directa Insegura a Objeto (IDOR), permitiendo a un atacante autenticado modificar el parámetro user en el cuerpo de la solicitud para inscribir a cualquier usuario arbitrario en cualquier curso sin las comprobaciones de autorización adecuadas. El backend confía en la entrada proporcionada por el usuario para el campo user y no realiza ninguna verificación del lado del servidor de que el solicitante posee el ID de usuario referenciado o tiene permiso para actuar en nombre de otros usuarios. Esto permite la manipulación no autorizada de las relaciones usuario-curso, lo que podría conceder acceso no intencionado a los materiales del curso, eludir los controles de inscripción y comprometer la integridad de la plataforma. Este problema ha sido solucionado en la versión 2.0.0-RC.3.

{"timestamp":"2026-04-15T13:32:25.460091Z","id":"CVE-2026-34602","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}

[{"vendor":"chamilo","product":"chamilo-lms","versions":[{"version":"< 2.0.0-RC.3","status":"affected"}]}]

OR
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha1:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha2:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha3:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha4:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:alpha5:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:beta1:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:beta2:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:beta3:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:rc1:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:2.0.0:rc2:*:*:*:*:*:*
          *cpe:2.3:a:chamilo:chamilo_lms:*:*:*:*:*:*:*:* versions up to (including) 1.11.38

GitHub, Inc.: https://github.com/chamilo/chamilo-lms/commit/2a9f060fa9d50fc9a92ed93af774d2619642df92 Types: Patch

GitHub, Inc.: https://github.com/chamilo/chamilo-lms/commit/bd2ba34c2e74475587e38c74c90c2934e69c8779 Types: Patch

GitHub, Inc.: https://github.com/chamilo/chamilo-lms/commit/c9c30cdc48afae57cd6ab012ae2eceafd351a40e Types: Patch

GitHub, Inc.: https://github.com/chamilo/chamilo-lms/releases/tag/v2.0.0-RC.3 Types: Product, Release Notes

GitHub, Inc.: https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-x373-8j9j-g5pj Types: Vendor Advisory

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.

AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

CWE-639

https://github.com/chamilo/chamilo-lms/commit/2a9f060fa9d50fc9a92ed93af774d2619642df92

https://github.com/chamilo/chamilo-lms/commit/bd2ba34c2e74475587e38c74c90c2934e69c8779

https://github.com/chamilo/chamilo-lms/commit/c9c30cdc48afae57cd6ab012ae2eceafd351a40e

https://github.com/chamilo/chamilo-lms/releases/tag/v2.0.0-RC.3

https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-x373-8j9j-g5pj