open-webui vulnerability

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, inline direct model metadata accepted client-supplied knowledge attachments without filtering them against the caller's read access. Any authenticated user who knew another user's file id could have the builtin knowledge tools return indexed chunks from that file, causing a read-only cross-user confidentiality loss while leaving knowledge-base permissions and saved workspace model validation unaffected. This issue is fixed in 0.11.0.

Published 4 Aug 2026Updated 18 Sep 20263 sources
CVSS 5.3

What happened

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, inline direct model metadata accepted client-supplied knowledge attachments without filtering them against the caller's read access. Any authenticated user who knew another user's file id could have the builtin knowledge tools return indexed chunks from that file, causing a read-only cross-user confidentiality loss while leaving knowledge-base permissions and saved workspace model validation unaffected. This issue is fixed in 0.11.0.

Affected versions

open-webui: >= 0.8.8, < 0.11.0 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.