Authorization bypass through user-controlled key in Open WebUI - #VU136847
Published: July 3, 2026
Vulnerability identifier: #VU136847
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-639
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 disclose sensitive information.
The vulnerability exists due to authorization bypass through user-controlled key in the channel thread message retrieval logic when handling a thread request with a caller-supplied message id. A remote user can request a thread in an accessible channel while supplying a private channel's message id as the thread root to disclose sensitive information.
The issue can expose the message content, channel id, and author metadata from a private channel, and direct access to the victim channel may still be denied.
Remediation
Install security update from vendor's website.