CVE-2026-44556
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the /responses endpoint in the OpenAI router accepts any authenticated user and forwards requests directly to upstream LLM providers without enforcing per-model access control. While the primary chat completion endpoint (generate_chat_completion) checks model ownership, group membership, and AccessGrants before allowing a request, the /responses proxy only validates that the user has a valid session via get_verified_user. This allows any authenticated user to interact with any model configured on the instance by sending a POST request to /api/openai/responses with an arbitrary model ID. This vulnerability is fixed in 0.9.0.
How to fix
- openwebui open_webui0.9.0 or later
- open-webui0.9.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| openwebui open_webui | v < 0.9.0 | 0.9.0 |
| open-webuiPyPI | v < 0.9.0 | 0.9.0 |
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Attack Surface Management
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