CVE-2026-44556
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | open-webui | <= 0.8.12 | 0.9.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Openwebui | Open Webui | before 0.9.0 |