CVE-2026-29056: Kanboard's privilege escalation via mass assignment in user invite registration allows any invited user to become admin

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-18 · updated 2026-06-17
Weakness: CWE-915

Description

Kanboard is project management software focused on Kanban methodology. Prior to 1.2.51, Kanboard's user invite registration endpoint (`UserInviteController::register()`) accepts all POST parameters and passes them to `UserModel::create()` without filtering out the `role` field. An attacker who receives an invite link can inject `role=app-admin` in the registration form to create an administrator account. Version 1.2.51 fixes the issue.

Affected products

kanboard: before 1.2.51 — fixed in 1.2.51

How to fix

Upgrade to a fixed version: kanboard 1.2.51. Check the vendor advisory for mitigations.

References

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