open-webui Open WebUI up to 0.9.4 Retrieval Query Endpoint /process/text _validate_collection_access authorization

Summaryinfo

A vulnerability was found in open-webui Open WebUI up to 0.9.4. It has been classified as problematic. The affected element is the function _validate_collection_access of the file /process/text of the component Retrieval Query Endpoint. The manipulation leads to authorization. This vulnerability is documented as CVE-2026-45398. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in open-webui Open WebUI up to 0.9.4 and classified as problematic. This issue affects the function _validate_collection_access of the file /process/text of the component Retrieval Query Endpoint. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-45398 since 05/12/2026. The exploitation is known to be difficult. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 0.9.5 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• open-webui

Name

• Open WebUI

Version

• 0.9.0
• 0.9.1
• 0.9.2
• 0.9.3
• 0.9.4

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CPE 2.2info

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