What’s Vulnerable › Vulnerabilities
CVE-2026-44550: Open WebUI: Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts
- Severity: medium (CVSS 5.0 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-862
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.
Affected products
- open-webui: before 0.9.0 — fixed in 0.9.0
How to fix
Upgrade to a fixed version: open-webui 0.9.0. Check the vendor advisory for mitigations.
References
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