CVE-2026-45398
HighSummary
In Open WebUI prior to version 0.9.5, a vulnerability allows authenticated users to access private knowledge bases by knowing the UUID. This flaw also enables attackers to inject or overwrite content in other users' knowledge bases.
Risk Assessment
The organization may be exposed to unauthorized access to sensitive data and the potential for content manipulation in knowledge bases, leading to loss of information integrity.
Recommendation
It is recommended to upgrade Open WebUI to version 0.9.5 or later to mitigate this vulnerability and secure access to knowledge bases.
Original NVD description (English source)
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, _validate_collection_access() checks the user-memory-* and file-* collection name prefixes but does not check knowledge base collections, which use raw UUIDs as collection names. Any authenticated user who knows a private knowledge base UUID can read its content through the retrieval query endpoints, even though the knowledge API correctly denies that user access. The same gap affects the retrieval write endpoints (/process/text, /process/file, /process/files/batch, /process/web, /process/youtube), allowing an attacker to inject content into or overwrite another user's knowledge base. This vulnerability is fixed in 0.9.5.