Open WebUI: Base Model Routing Bypasses Access Control via Model Chaining
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
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| open-webui | open-webui | affected |
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No data.
| Vendor | Product | Versions | ||||||||
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| Open-webui | Open-webui |
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| Source | ID | Title |
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Github GHSA |
GHSA-9vvh-qmjx-p4q8 | Open WebUI's Base Model Routing Bypasses Access Control via Model Chaining |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.304% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Openwebui
Openwebui open Webui |
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| CPEs | cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Openwebui
Openwebui open Webui |
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Open-webui
Open-webui open-webui |
|
| Vendors & Products |
Open-webui
Open-webui open-webui |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| Type | Values Removed | Values Added |
|---|---|---|
| Description | Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI supports model composition via base_model_id: a user-defined model (e.g., "Cheap Assistant") can reference an existing base model (e.g., "gpt-4-turbo-restricted") that provides the actual inference capability. When a user queries the composed model, the access control pipeline verifies the user has access to the composed model but never re-verifies access to the chained base model. Additionally, the model creation and import endpoints accept arbitrary base_model_id values without checking that the caller has access to that base model. Combined, this allows any user with the default model creation permission to create a model that chains to a restricted base model — and then invoke it, causing the server to dispatch the request to the restricted base model using the admin-configured API key. This vulnerability is fixed in 0.9.0. | |
| Title | Open WebUI: Base Model Routing Bypasses Access Control via Model Chaining | |
| Weaknesses | CWE-862 | |
| References |
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| Metrics |
cvssV3_1
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