The Repositories component in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allows remote attackers to conduct PHP object injection attacks and execute arbitrary code via serialized data associated with an add-on.

Multiple cross-site scripting (XSS) vulnerabilities in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allow remote attackers to inject arbitrary web script or HTML via vectors that trigger an AJAX exception dialog.

Multiple cross-site scripting (XSS) vulnerabilities in the advanced-grading implementation in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allow remote authenticated users to inject arbitrary web script or HTML via a crafted (1) qualification or (2) rating field in a rubric.

Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allows remote authenticated users to execute arbitrary code via a calculated question in a quiz.

The Shibboleth authentication plugin in auth/shibboleth/index.php in Moodle through 2.3.11, 2.4.x before 2.4.11, and 2.5.x before 2.5.7 does not check whether a session ID is empty, which allows remote authenticated users to hijack sessions via crafted plugin interaction.

Multiple cross-site scripting (XSS) vulnerabilities in badges/renderer.php in Moodle 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allow remote attackers to inject arbitrary web script or HTML via an external badge.

Cross-site scripting (XSS) vulnerability in user/profile.php in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allows remote authenticated users to inject arbitrary web script or HTML via the Skype ID profile field.

mod/imscp/locallib.php in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allows remote attackers to read arbitrary files via a package with a manifest file containing an XML external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue affecting IMSCP resources and the IMSCC format.

Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 does not enforce certain capability requirements in (1) notes/index.php and (2) user/edit.php, which allows remote attackers to obtain potentially sensitive username and course information via a modified URL.

mod/forum/classes/post_form.php in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 does not enforce the moodle/site:accessallgroups capability requirement before proceeding with a post to all groups, which allows remote authenticated users to bypass intended access restrictions by leveraging two or more group memberships.