CVE-2026-45399 Details
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, any authenticated user with low privileges can enumerate active background tasks across the system and stop tasks belonging to other users via the GET /api/tasks and POST /api/tasks/stop/{task_id} methods. This allows a casual user to disrupt system-wide chat usage by continuously canceling other users' active tasks. This is a real authorization vulnerability affecting integrity and usability in multi-user deployments. This vulnerability is fixed in 0.9.0.
A broken object-level authorization vulnerability has been identified in Open WebUI versions prior to 0.9.0. This vulnerability allows authenticated users with low privileges to enumerate and terminate active background tasks belonging to other users. The issue arises because the affected API endpoints do not verify task ownership, enabling users to disrupt system-wide chat functionality by canceling ongoing tasks. This vulnerability impacts the integrity and usability of the platform in multi-user environments.
Users can update to Open WebUI version 0.9.0 or later, where this vulnerability has been fixed. Instructions for updating can be found in the Open WebUI repository.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 15, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/open-webui/open-webui/security/advisories/GHSA-8jjp-r2w2-4v22 | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-8jjp-r2w2-4v22 | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-862 | Missing Authorization | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openwebui open webui | < 0.9.0 |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 19, 2026 | Initial Analysis | [email protected] |
| May 15, 2026 | New CVE Received | [email protected] |
| May 15, 2026 | CVE Modified | CISA-ADP |