CVE-2026-44556 Details
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.
A vulnerability exists in Open WebUI versions through 0.8.12, specifically within the OpenAI router's /responses endpoint. This endpoint allows any authenticated user to send requests to upstream LLM providers without proper access control for individual models. Unlike the main chat completion endpoint, which verifies model ownership and group membership, the /responses proxy only checks for a valid user session. As a result, authenticated users can interact with any model available on the instance by sending a POST request to /api/openai/responses with a chosen model ID. This issue could lead to unauthorized access and interaction with restricted models, causing potential service disruptions or unauthorized extraction of model capabilities.
Users can upgrade to Open WebUI version 0.9.0 or later to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 15, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/open-webui/open-webui/security/advisories/GHSA-hp5m-24vp-vq2q | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-284 | Improper Access Control | [email protected] |
| CWE-862 | Missing Authorization | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openwebui open webui | < 0.9.0 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 19, 2026 | Initial Analysis | [email protected] |
| May 15, 2026 | New CVE Received | [email protected] |