| Component | Open WebUI |
| Severity | high (CVSS 8.1) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| Published (NVD) | 2026-05-15 |
| Last modified | 2026-06-17 |
| Affected versions | open_webui < 0.9.5 |
| Fixed in | 0.9.5 |
| Weakness | CWE-639 |
| CISA KEV | not listed |
NVD description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, multiple endpoints accept a user-supplied file_id and attach the referenced file to a resource the caller controls (folder knowledge, knowledge-base contents) without verifying that the caller owns or has been granted access to the file. The file's content then becomes reachable through the downstream RAG / file-content paths, allowing any authenticated user to exfiltrate any other user's private file — and on the knowledge-base path, also to overwrite it — given knowledge of the file's UUID. This affects backend/open_webui/routers/folders.py (POST /api/v1/folders/{id}/update), backend/open_webui/routers/knowledge.py (add_file_to_knowledge_by_id), and backend/open_webui/routers/knowledge.py (add_files_to_knowledge_by_id_batch). This vulnerability is fixed in 0.9.5.
What to do
- Upgrade Open WebUI to
0.9.5or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
Read more
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