The PraisonAI Platform's PATCH /workspaces/{workspace_id}/members/{user_id} endpoint is protected by a check requiring the caller to be at least a workspace member, but this check does not enforce stricter role requirements. The endpoint handler calls MemberService.update_role to set the target user's role based solely on the request body, without verifying that the caller has owner or admin privileges, or that the new role is not higher than the caller's own role. This flaw enables vertical privilege escalation by allowing unauthorized role changes, including self-promotion. The vulnerability affects all versions prior to 0.1.4, which includes the fix.

An attacker with member-level access to a workspace can escalate their privileges to owner or admin roles without authorization. This results in a complete compromise of workspace access control, allowing unauthorized access to sensitive data and administrative functions. The vulnerability has a CVSS 3.1 base score of 9.6 (critical), indicating high impact on confidentiality and integrity with no impact on availability.

Upgrade to PraisonAI Platform version 0.1.4 or later, which patches the privilege escalation vulnerability by enforcing proper role checks on the PATCH /workspaces/{workspace_id}/members/{user_id} endpoint. Since no official remediation level or patch link is provided, verify the upgrade from the vendor's official release notes or repository. Until patched, restrict access to the affected endpoint to trusted users only, if possible.