CVE-2026-44552
HighSummary
In versions prior to 0.9.0 of Open WebUI, the tool_servers and terminal_servers keys in utils/tools.py do not use a prefix, leading to key collisions when multiple instances share a Redis database. This can result in one instance overwriting the tool server configuration of another instance.
Risk Assessment
Organizations may experience unauthorized access to tool server configurations, potentially leading to application malfunction and user data loss.
Recommendation
It is recommended to upgrade Open WebUI to version 0.9.0 or later to eliminate the key collision issue in Redis.
Original NVD description (English source)
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the tool_servers and terminal_servers keys in utils/tools.py do use a prefix. When two or more Open WebUI instances share a Redis database (a supported and documented deployment pattern, e.g., for multi-region deployments, blue-green setups, or cluster topologies), the unprefixed keys collide. An admin on Instance A writing to tool_servers overwrites the value read by Instance B — causing Instance B's users to receive Instance A's tool server configuration. This vulnerability is fixed in 0.9.0.