CVE-2026-59715: Open WebUI missing authentication in Socket.IO document handlers

Executive brief

Open WebUI is an interface for interacting with large language models that includes collaborative document editing features. A security flaw in its communication system allows unauthorized users to join document sessions without proper credentials. This can be used to impersonate legitimate users, disrupt the user interface with fake cursor movements, or potentially overwhelm the server with fake connections.

Technical details

The Socket.IO server in Open WebUI is configured with 'always_connect=True' and lacks authentication enforcement in the 'connect' handler. Specifically, the 'ydoc:awareness:update' and 'ydoc:document:leave' event handlers do not verify session membership or user identity. An attacker can connect via WebSockets without a token and emit spoofed events to broadcast fake cursor positions, selections, or 'user left' notifications to legitimate participants in a document room. This is classified as CWE-306 (Missing Authentication for Critical Function). The issue is resolved in version 0.10.0.

Affected products

• Open WebUI open-webui >= 0.6.16, < 0.10.0

Timeline

• 2026-07-02: disclosed
• 2026-07-09: advisory: NVD publication date
• 2026-07-24: patched: GitHub Advisory reviewed/updated

References

• https://api.github.com/users/sfwani
• https://github.com/sfwani
• https://api.github.com/users/sfwani/gists%7B/gist_id%7D
• https://api.github.com/users/sfwani/repos
• https://avatars.githubusercontent.com/u/128927952?v=4
• https://api.github.com/users/sfwani/events%7B/privacy%7D