Improper access control in MantisBT - CVE-2026-34390
Published: November 6, 2026
Vulnerability identifier: #VU159808
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-34390
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker with project-management privileges to gain project-level administrator access in MantisBT.
The vulnerability exists due to insufficient access checks in the project-user addition handler when processing a forged higher access level. A remote attacker with project-management privileges can submit a crafted request to grant this role to themselves or others in projects where they meet manage_project_threshold (manager by default), without gaining instance-wide administrative privileges.
Affected software
MantisBT
How to mitigate CVE-2026-34390
Install security update from vendor's website.
MantisBT - update to 2.28.2