cvedb.io
CVE-2026-28788
HIGH · CVSS 7.1
EPSS exploitation probability: 0%
Published 2026-03-27T00:16:22.673 · Last modified 2026-06-17T10:29:02.773

Summary

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, any authenticated user can overwrite any file's content by ID through the `POST /api/v1/retrieval/process/files/batch` endpoint. The endpoint performs no ownership check, so a regular user with read access to a shared knowledge base can obtain file UUIDs via `GET /api/v1/knowledge/{id}/files` and then overwrite those files, escalating from read to write. The overwritten content is served to the LLM via RAG, meaning the attacker controls what the model tells other users. Version 0.8.6 patches the issue.

Affected products

openwebui — open_webui

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.