mod/lti/ajax.php in Moodle through 2.5.9, 2.6.x before 2.6.7, 2.7.x before 2.7.4, and 2.8.x before 2.8.2 does not consider the moodle/course:manageactivities and mod/lti:addinstance capabilities before proceeding with registered-tool list searches, which allows remote authenticated users to obtain sensitive information via requests to the LTI Ajax service.

login/confirm.php in Moodle through 2.5.9, 2.6.x before 2.6.11, 2.7.x before 2.7.8, and 2.8.x before 2.8.6 allows remote authenticated users to bypass intended login restrictions by leveraging access to an unconfirmed suspended account.

message/index.php in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4 does not consider the moodle/site:readallmessages capability before accessing arbitrary conversations, which allows remote authenticated users to obtain sensitive personal-contact and unread-message-count information via a modified URL.

Cross-site scripting (XSS) vulnerability in the external_format_text function in lib/externallib.php in Moodle through 2.5.9, 2.6.x before 2.6.11, 2.7.x before 2.7.8, and 2.8.x before 2.8.6 allows remote authenticated users to inject arbitrary web script or HTML into an external application via a crafted string that is visible to web services.

Multiple cross-site request forgery (CSRF) vulnerabilities in (1) editcategories.html and (2) editcategories.php in the Glossary module in Moodle through 2.5.9, 2.6.x before 2.6.7, 2.7.x before 2.7.4, and 2.8.x before 2.8.2 allow remote attackers to hijack the authentication of unspecified victims.

The account-confirmation feature in login/confirm.php in Moodle through 2.5.9, 2.6.x before 2.6.11, 2.7.x before 2.7.8, and 2.8.x before 2.8.6 allows remote attackers to obtain sensitive full-name information by attempting to self-register.

filter/urltolink/filter.php in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4 allows remote authenticated users to cause a denial of service (CPU consumption or partial outage) via a crafted string that is matched against an improper regular expression.

Multiple cross-site scripting (XSS) vulnerabilities in lib/javascript-static.js in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4 allow remote authenticated users to inject arbitrary web script or HTML via a (1) alt or (2) title attribute in an IMG element.

files/externallib.php in Moodle through 2.5.9, 2.6.x before 2.6.11, 2.7.x before 2.7.8, and 2.8.x before 2.8.6 does not consider the moodle/user:manageownfiles capability before approving a private-file upload, which allows remote authenticated users to bypass intended file-management restrictions by using web services to perform uploads after this capability has been revoked.

filter/mediaplugin/filter.php in Moodle through 2.5.9, 2.6.x before 2.6.7, 2.7.x before 2.7.4, and 2.8.x before 2.8.2 allows remote authenticated users to cause a denial of service (CPU consumption or partial outage) via a crafted string that is matched against an improper regular expression.