CVE-2026-45666: Open WebUI: Indirect Object Reference (IDOR) in user notes

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-15 · updated 2026-06-17
Weakness: CWE-639

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.11, the API /api/v1/notes/{note_id} endpoint lacks proper authorization checks, allowing authenticated users to retrieve notes belonging to other users by guessing or enumerating UUIDs. This results in unauthorized disclosure of potentially sensitive or private user data. This vulnerability is fixed in 0.8.11.

Affected products

open-webui: before 0.8.11 — fixed in 0.8.11

How to fix

Upgrade to a fixed version: open-webui 0.8.11. Check the vendor advisory for mitigations.

References

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