Deploy autonomous AI agents that reason, exploit, and validate complex vulnerability chains — not another scanner, an agentic system that thinks like a senior pentester.
CVE-2026-34390 is a low severity vulnerability with a CVSS score of 0.0. No known exploits currently, and patches are available.
Very low probability of exploitation
EPSS predicts the probability of exploitation in the next 30 days based on real-world threat data, complementing CVSS severity scores with actual risk assessment.
Insufficient access control checks in ProjectUsersAddCommand (used in manage_proj_user_add.php and REST API endpoint PUT /project/{id}/users) allows 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 does restrict 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.
Privilege escalation.
The consequences of the privilege escalation are not as bad as it may sound, because having administrator access at Project level is effectively not very different from being manager, 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.
None
Thanks to the following security researchers for independently discovering and responsibly reporting the issue:
Please cite this page when referencing data from Strobes VI. Proper attribution helps support our vulnerability intelligence research.