Improper access control in Open WebUI - #VU130176
Published: May 5, 2026
Vulnerability identifier: #VU130176
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Open WebUI
Affected software:
Open WebUI
Open WebUI
Detailed vulnerability description
The vulnerability allows a remote user to modify collaborative documents and cause a denial of service.
The vulnerability exists due to improper access control in the ydoc:document:update Socket.IO event handler when handling collaborative document update events from users who have only joined the document room with read permission. A remote user can send a specially crafted Socket.IO update event to modify collaborative documents and cause a denial of service.
If a user with write access saves the document, the tampered content may be persisted. The issue affects in-memory Yjs document state and the changes are broadcast to other collaborators in real time.
Remediation
Install security update from vendor's website.