CVE-2026-45402 Details
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, multiple endpoints accept a user-supplied file_id and attach the referenced file to a resource the caller controls (folder knowledge, knowledge-base contents) without verifying that the caller owns or has been granted access to the file. The file's content then becomes reachable through the downstream RAG / file-content paths, allowing any authenticated user to exfiltrate any other user's private file — and on the knowledge-base path, also to overwrite it — given knowledge of the file's UUID. This affects backend/open_webui/routers/folders.py (POST /api/v1/folders/{id}/update), backend/open_webui/routers/knowledge.py (add_file_to_knowledge_by_id), and backend/open_webui/routers/knowledge.py (add_files_to_knowledge_by_id_batch). This vulnerability is fixed in 0.9.5.
A vulnerability in Open WebUI versions prior to 0.9.5 allows authenticated users to access and exfiltrate private files belonging to other users through unchecked file_id references in knowledge management endpoints. The issue arises because multiple endpoints accept user-supplied file_ids and attach the corresponding files to resources controlled by the caller, without verifying ownership or access rights. This flaw enables file content to be accessed via downstream paths, potentially leading to unauthorized data exposure or overwriting of files in the knowledge base.
Users are advised to update Open WebUI to version 0.9.5 or later, where this vulnerability has been fixed.
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 18, 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-r472-mw7m-967f | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-r472-mw7m-967f | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-639 | Authorization Bypass Through User-Controlled Key | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openwebui open webui | < 0.9.5 |
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 18, 2026 | Initial Analysis | [email protected] |
| May 15, 2026 | CVE Modified | CISA-ADP |
| May 15, 2026 | New CVE Received | [email protected] |