CVE-2026-45398
Open WebUI: IDOR - Retrieval API Bypasses Knowledge Base Access Controls
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.
INFO
Published Date :
May 15, 2026, 9:16 p.m.
Last Modified :
Nov. 11, 2026, 8:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-45398
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Open WebUI to version 0.9.5 or later.
- Verify access controls on all knowledge bases.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-45398.
| URL | Resource |
|---|---|
| https://github.com/open-webui/open-webui/pull/22109 | Issue Tracking Patch |
| https://github.com/open-webui/open-webui/releases/tag/v0.9.5 | Release Notes |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 | Exploit Mitigation Vendor Advisory |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-45398 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-45398
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-45398 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-45398 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Nov. 11, 2026
Action Type Old Value New Value Added Translation Title: Open-webui, Description: Open WebUI es una plataforma de inteligencia artificial autoalojada diseñada para operar completamente sin conexión. Antes de la versión 0.9.5, _validate_collection_access() verifica los prefijos de nombres de colección ’user-memory-*’ y ’file-*’ pero no verifica las colecciones de bases de conocimiento, que utilizan UUIDs sin procesar como nombres de colección. Cualquier usuario autenticado que conozca un UUID de una base de conocimiento privada puede leer su contenido a través de los puntos finales de consulta de recuperación, aunque la API de conocimiento deniega correctamente el acceso a ese usuario. La misma brecha afecta a los puntos finales de escritura de recuperación (/process/text, /process/file, /process/files/batch, /process/web, /process/youtube), permitiendo a un atacante inyectar contenido o sobrescribir la base de conocimiento de otro usuario. Esta vulnerabilidad se corrige en la versión 0.9.5. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'open-webui', 'product': 'open-webui', 'versions': [{'status': 'affected', 'version': '< 0.9.5'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-45398', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-18T00:00:00+00:00'} -
Initial Analysis by [email protected]
May. 19, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* versions up to (excluding) 0.9.5 Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/pull/22109 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/releases/tag/v0.9.5 Types: Release Notes Added Reference Type CISA-ADP: https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 Types: Exploit, Mitigation, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 Types: Exploit, Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 18, 2026
Action Type Old Value New Value Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9 -
New CVE Received by [email protected]
May. 15, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-639 Added Reference https://github.com/open-webui/open-webui/pull/22109 Added Reference https://github.com/open-webui/open-webui/releases/tag/v0.9.5 Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9