The LinkedCustomFields plugin for MantisBT allows users to link values between two custom fields, creating linked drop-downs. Prior to version 2.0.1, cross-site scripting in the MantisBT LinkedCustomFields plugin allows Javascript execution, when a crafted Custom Field is linked via the plugin and displayed when reporting a new Issue or editing an existing one. This issue is fixed in version 2.0.1. As a workaround, one may utilize MantisBT's default Content Security Policy, which blocks script execution.

An issue was discovered in the Source Integration plugin before 2.4.1 for MantisBT. An attacker can gain access to the Summary field of private Issues (either marked as Private, or part of a private Project), if they are attached to an existing Changeset. The information is visible on the view.php page, as well as on the list.php page (a pop-up on the Affected Issues id hyperlink). Additionally, if the attacker has "Update threshold" in the plugin's configuration (set to the "updater" access level by default), then they can link any Issue to a Changeset by entering the Issue's Id, even if they do not have access to it.

An issue was discovered in the Source Integration plugin before 1.5.9 and 2.x before 2.1.5 for MantisBT. A cross-site scripting (XSS) vulnerability in the Manage Repository and Changesets List pages allows execution of arbitrary code (if CSP settings permit it) via repomanagepage.php or list.php.

Cross-site request forgery (CSRF) vulnerability in manageusercreate.php in Mantis 1.1.1 allows remote attackers to create new administrative users via a crafted link.