| Component | Open WebUI, LangChain |
| Severity | high (CVSS 8.5) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/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-918 |
| 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, the validate_url() function in backend/open_webui/retrieval/web/utils.py only validates the initial URL submitted by the caller. The HTTP clients used downstream (sync requests, async aiohttp, langchain's WebBaseLoader) follow HTTP 3xx redirects by default and do not re-validate the redirect target against the private-IP / metadata-IP block list. Any authenticated user can therefore submit a public URL that 302-redirects to an internal address (e.g. 127.0.0.1, 169.254.169.254, RFC1918) and read the internal response body via the /api/v1/retrieval/process/web endpoint, the /api/v1/images/... endpoints, the /api/chat/completions endpoint with an image_url content part, and any other route that calls these helpers. 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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