Chamilo LMS is a learning management system. Prior to 1.11.38 and 2.0.0-RC.3, in main/lp/aicc_hacp.php, user-controlled request parameters are directly used to set the PHP session ID before loading global bootstrap. This leads to session fixation. This vulnerability is fixed in 1.11.38 and 2.0.0-RC.3.
https://github.com/chamilo/chamilo-lms/security/advisories/GHSA-4gp7-cfjh-77gv
https://github.com/chamilo/chamilo-lms/commit/e337b7cc74a0276a0b4f91f9282204d20cac1869
https://github.com/chamilo/chamilo-lms/commit/ce0192c62e48c9d9474d915c541b3274844afbf9