mediumCVSS 6.5Vulnerability

CVE-2026-45666

### Summary 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. ### Details - if notes is enabled from UI (Settings >> General >> Features >> Notes (Beta)) - From API, attacker can access other user notes - if notes is disabled from UI (Settings >> General >> Features >> Notes (Beta)) - Then attacker can enable the notes from /api/config and access other user notes ### PoC - Step 1: Log in to the application as a valid user (User A). ![image](https://github.com/user-attachments/assets/3c4625f9-6e51-4cd1-942e-6a3f467520c0) - Step 2: Intercept or inspect the response from the endpoint GET /api/config. ![image](https://github.com/user-attachments/assets/7c4fe716-314c-4640-bc9f-1e11ddc2273d) - Step 3: Observe the field "enable_notes": false in the JSON response. - Step 4: Manually change "enable_notes" to true using browser DevTools or by intercepting and modifying the response via a proxy like Burp Suite. (Please note, the occurrence of this API comes twice, hence modification needs to be made twice as well.) ![image](https://github.com/user-attachments/assets/99575570-a673-4508-b149-9a2480d8f62e) - Step 5: Observe the loaded frontend application; the previously hidden notes form will now be visible. ![image](https://github.com/user-attachments/assets/a4059b1f-2e77-4f29-88a3-431e82b7c41d) ![image](https://github.com/user-attachments/assets/55e601d7-b013-43e3-a070-3a80f166e777) - Step 6: Again, click on any note, intercept the request, and Replace the note_id in the URL with a different note ID known to belong to another user (e.g., by guessing or bruteforcing). - Step 7: Send the modified request while remaining logged in as User A. - Step 8: Observe that the server returns the content of another user's note, confirming unauthorized access.

Properties

severity
medium
summary
Open WebUI has an Indirect Object Reference (IDOR) in user notes
epss_score
0.00277
cvss_score
6.5
ghsa_published
2026-05-14T20:27:56Z
source_url
https://github.com/advisories/GHSA-x3qm-p8hr-3c3h
ghsa_updated
2026-05-19T16:00:34Z
ghsa_id
GHSA-x3qm-p8hr-3c3h
cve_id
CVE-2026-45666
cvss_vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
is_ghsa_only
false
epss_percentile
0.20023

Related Entities (5)

ENRICHED_BY (1)

[Source]FIRST EPSS

HAS_WEAKNESS (1)

[Weakness]Authorization Bypass Through User-Controlled Key

REPORTED_BY (1)

[Source]GitHub Advisory Database

VULNERABLE_TO (1)

[Software]pip/open-webui

AFFECTS (1)

[Software]pip/open-webui

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CVE-2026-45666 (CVSS 6.5) — Ninja Signal Threat Intelligence | Ninja Signal