The PraisonAI Platform's `POST /workspaces/{workspace_id}/members` endpoint is protected only by a minimal role check (`min_role="member"`) and directly passes the request's `user_id` and `role` parameters to `MemberService.add` without verifying the caller's permission to assign roles. This flaw allows a user with the lowest workspace privilege to add any user, including attacker-controlled accounts, as an owner of the workspace, resulting in privilege escalation and cross-tenant member injection. The vulnerability affects versions prior to 0.1.4 and is addressed in version 0.1.4.

An attacker with minimal privileges in a workspace can escalate their privileges to owner by adding users with elevated roles, potentially compromising workspace integrity and confidentiality. This can lead to unauthorized access and control over workspace resources. The vulnerability does not affect availability but has high impact on confidentiality and integrity.

Upgrade PraisonAI Platform to version 0.1.4 or later, where this privilege escalation vulnerability is patched. No other mitigation is indicated by the vendor advisory. Patch status is not explicitly confirmed beyond the version update, so verify with vendor resources for the latest remediation guidance.