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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.

PUBLISHED Reserved 2026-03-30 | Published 2026-04-14 | Updated 2026-04-15 | Assigner GitHub_M




HIGH: 7.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Problem types

CWE-639: Authorization Bypass Through User-Controlled Key

Product status

< 2.0.0-RC.3
affected

References

github.com/...lo-lms/security/advisories/GHSA-x373-8j9j-g5pj

github.com/...ommit/2a9f060fa9d50fc9a92ed93af774d2619642df92

github.com/...ommit/bd2ba34c2e74475587e38c74c90c2934e69c8779

github.com/...ommit/c9c30cdc48afae57cd6ab012ae2eceafd351a40e

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

cve.org (CVE-2026-34602)

nvd.nist.gov (CVE-2026-34602)

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