CVE-2026-34390

What it is

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.

At a glance

Exploitability

Can be exploited over the network with an admin-level account. Limited direct impact.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-19 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-24 09:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 5.1 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-19 22:16 UTC

Last modified

2026-07-24 09:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-284 · Improper access control

Record status

Deferred

Attack profile CVSS 4.0 · 5.1

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

High

User interaction

None

Confidentiality

Low

Integrity

Low

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-34390.md and follow it. Check whether this project is affected by CVE-2026-34390. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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