CVE-2026-109287: Open WebUI authorization flaw in knowledge base file listing

CVE-2026-109287 · Severity: medium · CVSS 4.3 · Published 2026-10-12

Open WebUI is a web interface for managing document collections and knowledge bases. A flaw in its authorization checks allows users who have access to one knowledge base to view the folder structure and metadata (owner IDs, knowledge base IDs, timestamps) of other knowledge bases they should not access, by reusing a previously known directory identifier. This information disclosure does not expose file contents but reveals sensitive organizational structure.

Technologies: Open WebUI. Vendors: Open WebUI.

Quick answers

Is CVE-2026-109287 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-109287 being exploited in the wild.
How severe is CVE-2026-109287?
Medium severity, with a CVSS score of 4.3, published 12 October 2026.
Which products and versions are affected?
Open WebUI 0.9.6 to before 0.11.4.
Is there a fix for CVE-2026-109287?
Yes: fixed in 0.11.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-109287 attacked?
It is attacked over the network.
Am I affected by CVE-2026-109287?
Check whether you run Open WebUI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Fixed in: 0.11.4

Technical details

The vulnerability is an authorization bypass in multiple API endpoints that handle knowledge base directory operations: GET /api/v1/knowledge/{id}/files, POST /{id}/dirs/create, POST /{id}/dirs/{dir_id}/update, and POST /{id}/file/add. These endpoints verify the caller's access to the named knowledge base but fail to validate that a caller-supplied directory_id or parent_id belongs to that same knowledge base, allowing attackers to reference directories from other knowledge bases. The breadcrumb walk function retrieves directories by ID alone without checking their knowledge base association, leaking metadata including folder names, owner user IDs, and ancestor information for inaccessible knowledge bases.

Affected products

  • Open WebUI Open WebUI 0.9.6 to before 0.11.4

Timeline

  • 2026-09-27: disclosed
  • 2026-10-12: advisory

References

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