Junglewise Threat Intelligence

CVE-2026-34390: MantisBT privilege escalation in ProjectUsersAddCommand

CVE-2026-34390 · Severity: medium · CVSS 5.1 · Published 2026-05-19

Technologies: MantisBT Mantis Bug Tracker, mantisbt/mantisbt (Packagist). Vendors: MantisBT, Packagist.

Executive brief

MantisBT, a popular open-source bug tracking system, contains a vulnerability that allows project managers to elevate their own or others' privileges to project-level administrator. While this does not grant full system-wide administrative control, it allows unauthorized access to project-specific settings. This could lead to unauthorized configuration changes within specific projects.

Technical details

A privilege escalation vulnerability exists in MantisBT's ProjectUsersAddCommand, affecting both the web UI (manage_proj_user_add.php) and the REST API (PUT /project/{id}/users). While the frontend UI restricts selectable access levels based on the user's role, the backend fails to validate the 'access_level' parameter in the request. An attacker with 'manager' privileges can submit a forged request to assign the 'administrator' role at the project level. This role is limited to project-specific actions and does not grant global instance-wide administrative rights. The issue is fixed in version 2.28.2.

Affected products

  • MantisBT MantisBT <= 2.28.1

Timeline

  • 2026-05-09: disclosed
  • 2026-05-11: advisory: GitHub Advisory published
  • 2026-05-19: other: NVD published

References

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