The vulnerability allows a user who has read access to any knowledge base to retrieve the breadcrumb hierarchy of an unrelated directory by supplying a foreign directory ID to the /api/v1/knowledge/{id}/files endpoint. This results in disclosure of folder names, owner user IDs, and knowledge base IDs for that directory and all its ancestors, leaking internal structure and potentially user identities. The weakness is identified as an authorization bypass that fails to verify that the supplied directory_id belongs to the requested knowledge base.

Open WebUI versions from 0.9.6 through 0.11.3 are affected. The issue is present on installations where users can read at least one knowledge base. Upgrading to 0.11.4 or later removes the flaw.

The CVSS score of 5.3 indicates a moderate risk level. Because the malicious request can be sent over the network to any exposed instance of WebUI, attackers with read access to a knowledge base can easily enumerate sensitive information without needing elevated privileges. The EPSS score is 0.00222, indicating a very low exploitation probability, but the lack of KEV listing suggests that no widespread exploitation has been documented yet. Nonetheless, the potentially exposed user identifiers and knowledge base relationships warrant rapid remediation.