CVE-2026-45398 Details
Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, _validate_collection_access() checks the user-memory-* and file-* collection name prefixes but does not check knowledge base collections, which use raw UUIDs as collection names. Any authenticated user who knows a private knowledge base UUID can read its content through the retrieval query endpoints, even though the knowledge API correctly denies that user access. The same gap affects the retrieval write endpoints (/process/text, /process/file, /process/files/batch, /process/web, /process/youtube), allowing an attacker to inject content into or overwrite another user's knowledge base. This vulnerability is fixed in 0.9.5.
A vulnerability in Open WebUI prior to version 0.9.5 allows authenticated users to bypass knowledge base access controls. The issue arises because the function that validates collection access does not check knowledge base collections, which are identified by UUIDs. As a result, any authenticated user who knows a private knowledge base UUID can access its content through retrieval query endpoints. This vulnerability also affects write endpoints, enabling users to inject or overwrite content in another user's knowledge base.
Users can update to Open WebUI 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-4g37-7p2c-38r9 | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/open-webui/open-webui/pull/22109 | [email protected] | Issue TrackingPatch |
| https://github.com/open-webui/open-webui/releases/tag/v0.9.5 | [email protected] | Release Notes |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 | [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
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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 18, 2026 | CVE Modified | CISA-ADP |
| May 15, 2026 | New CVE Received | [email protected] |