Missing Authorization in Open WebUI - CVE-2026-45399
Published: May 11, 2026
Vulnerability identifier: #VU130952
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-45399
CWE-ID: CWE-862
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to missing authorization in the /api/tasks and /api/tasks/stop/{task_id} endpoints when handling authenticated requests to list and stop tasks. A remote user can enumerate global task IDs and stop tasks belonging to other users to cause a denial of service.
This affects multi-user deployments and also exposes task IDs belonging to other users.
Affected software
Open WebUI
How to mitigate CVE-2026-45399
Install security update from vendor's website.
Open WebUI - update to 0.9.0