user/index.php in Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 grants excessive authorization on the basis of the moodle/course:viewhiddenuserfields capability, which allows remote authenticated users to discover student e-mail addresses by leveraging the teacher role and reading a Participants list.

The grade-reporting feature in Singleview (aka Single View) in Moodle 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 does not consider the moodle/grade:manage capability, which allows remote authenticated users to modify "Exclude grade" settings by leveraging the Non-Editing Instructor role.

The lesson module in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 allows remote authenticated users to bypass intended access restrictions and enter additional answer attempts by leveraging the student role.

Cross-site request forgery (CSRF) vulnerability in admin/registration/register.php in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 allows remote attackers to hijack the authentication of administrators for requests that send statistics to an arbitrary hub URL.

Cross-site scripting (XSS) vulnerability in group/overview.php in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 allows remote authenticated users to inject arbitrary web script or HTML via a modified grouping description.

Multiple cross-site scripting (XSS) vulnerabilities in the survey module in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 allow remote authenticated users to inject arbitrary web script or HTML by leveraging the student role and entering a crafted survey answer.

Multiple cross-site scripting (XSS) vulnerabilities in the SCORM module in Moodle through 2.6.11, 2.7.x before 2.7.9, 2.8.x before 2.8.7, and 2.9.x before 2.9.1 allow remote attackers to inject arbitrary web script or HTML via a crafted organization name to (1) mod/scorm/player.php or (2) mod/scorm/prereqs.php.

The choice module in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 allows remote authenticated users to bypass intended access restrictions by visiting a URL to add or delete responses in the closed state.

The enrol_meta_sync function in enrol/meta/locallib.php in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 allows remote authenticated users to obtain manager privileges in opportunistic circumstances by leveraging incorrect role processing during a long-running sync script.

Multiple cross-site request forgery (CSRF) vulnerabilities in the lesson module in Moodle through 2.6.11, 2.7.x before 2.7.11, 2.8.x before 2.8.9, and 2.9.x before 2.9.3 allow remote attackers to hijack the authentication of arbitrary users for requests to (1) mod/lesson/mediafile.php or (2) mod/lesson/view.php.