Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior have a Privilege Escalation vulnerability where insufficient access control checks in ProjectUsersAddCommand (manage_proj_user_add.php) allow users having manage_project_threshold access level (manager by default) to grant project-level administrator access to any user (including themselves) in any Project they have manager rights in. The normal project-user add form restricts the selectable access levels to the actor's own project role or below. However, the backend handler still accepts a forged higher access_level value and writes it. The consequences of the privilege escalation are slight, as having administrator access at Project level is effectively not very different from being manager, and it does not actually give administrator privileges on the whole MantisBT instance. In particular, it does not let the upgraded user delete the Project or grant them any access to global administrative functions such as managing Users, Projects, Plugins, Custom Fields, etc. This issue has been fixed in version 2.28.2.

The version of MantisBT installed on the remote host is prior to 2.28.2. It is, therefore, affected by multiple vulnerabilities:

  - MantisBT is vulnerable to Privilege Escalation from Manager to Administrator. (CVE-2026-34390)

  - MantisBT is vulnerable to Authorization Bypass in Bugnote Editing via Issue Update API. (CVE-2026-42070)

  - MantisBT is vulnerable to Stored XSS in Custom Field Textarea Values. (CVE-2026-39960)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior have a Privilege
    Escalation vulnerability where insufficient access control checks in ProjectUsersAddCommand
    (manage_proj_user_add.php) allow users having manage_project_threshold access level (manager by default)
    to grant project-level administrator access to any user (including themselves) in any Project they have
    manager rights in. The normal project-user add form restricts the selectable access levels to the actor's
    own project role or below. However, the backend handler still accepts a forged higher access_level value
    and writes it. The consequences of the privilege escalation are slight, as having administrator access at
    Project level is effectively not very different from being manager, and it does not actually give
    administrator privileges on the whole MantisBT instance. In particular, it does not let the upgraded user
    delete the Project or grant them any access to global administrative functions such as managing Users,
    Projects, Plugins, Custom Fields, etc. This issue has been fixed in version 2.28.2. (CVE-2026-34390)

ID	Name	Product	Family	Severity
315202	MantisBT < 2.28.2 Multiple Vulnerabilities	Nessus	CGI abuses : XSS	high
441748	SCA: security update for mantisbt/mantisbt (GHSA-frf7-jhp9-jxm6)	Tenable Cloud Security	SCA Checks	medium
441748	SCA: security update for mantisbt/mantisbt (GHSA-frf7-jhp9-jxm6)	Tenable Self-Hosted Container Security	SCA Checks	medium

Detections

Analytics

CVE-2026-34390

medium

Tenable Plugins

high

medium

medium