CVE-2026-28788

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.

The following products are affected by CVE-2026-28788 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-28788.

URL	Resource
https://github.com/open-webui/open-webui/security/advisories/GHSA-jjp7-g2jw-wh3j