Flowise versions prior to 3.1.0 are vulnerable to an access control flaw that permits authenticated users to overwrite and hijack DocumentStore objects across workspaces.

This is a mass assignment vulnerability (CWE-915) combined with improper access control (CWE-284). By controlling the primary key during the creation of a DocumentStore entity, an authenticated user can trigger an implicit update operation that modifies or overwrites existing objects belonging to other workspaces or tenants.

The ability to perform cross-workspace object modification poses a significant risk to data integrity and confidentiality in multi-tenant environments. An attacker could potentially gain unauthorized access to proprietary large language model flows or disrupt service availability for other users. With a CVSS score of 8.8, this high-severity vulnerability necessitates immediate attention to prevent unauthorized data manipulation.

Immediate Action: Update Flowise to version 3.1.0 or later to include the required security patches for the DocumentStore endpoint.

Proactive Monitoring: Review audit logs for unusual POST requests to the DocumentStore creation endpoint, specifically looking for unexpected primary key (id) assignments or high volumes of object creation activity.

Compensating Controls: Implement strict object-level authorization checks at the application layer or utilize a Web Application Firewall (WAF) to filter requests that attempt to modify sensitive internal state fields.

Public Exploit Available: Unknown.

Given the potential for cross-tenant data compromise, administrators should prioritize upgrading to version 3.1.0 immediately. Organizations operating multi-tenant Flowise instances are at the highest risk and should verify that all workspace isolation controls are functioning as expected following the update.