Missing Authorization in Open WebUI - #VU130241
Published: May 6, 2026
Vulnerability identifier: #VU130241
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-862
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 other users' messages.
The vulnerability exists due to improper authorization in the POST /api/v1/channels/{channel_id}/messages/{message_id}/update endpoint when handling update requests for messages in standard channels. A remote user can send a specially crafted update request to modify other users' messages.
Exploitation requires a standard channel whose channel.type is neither group nor dm, with access_control set to None or otherwise allowing read access, and knowledge of the target message_id.
Remediation
Install security update from vendor's website.