Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.
Mantis Bug Tracker (MantisBT) is an open source issue tracker. Using a crafted POST request, an unprivileged, registered user is able to retrieve information about other users' personal system profiles. This vulnerability is fixed in 2.26.4.