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.
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Fri, 15 May 2026 23:15:00 +0000
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Fri, 15 May 2026 21:45:00 +0000
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Open-webui
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Fri, 15 May 2026 20:15:00 +0000
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| 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. | |
| Title | Open WebUI: responses passthrough endpoint lacks access control authorization | |
| Weaknesses | CWE-284 CWE-862 |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-05-15T19:46:17.750Z
Updated: 2026-05-15T22:21:46.573Z
Reserved: 2026-05-06T20:59:00.594Z
Link: CVE-2026-44556
Updated: 2026-05-15T22:15:08.094Z
Status : Received
Published: 2026-05-15T20:16:47.097
Modified: 2026-05-15T20:16:47.097
Link: CVE-2026-44556
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