Access Control Vulnerability in Open WebUI by Open WebUI
CVE-2026-44557

4.3MEDIUM

Key Information:

Vendor

Open-webui

Status
Open-webui
Vendor
CVE Published:
15 May 2026

What is CVE-2026-44557?

Open WebUI, a self-hosted AI platform, had a significant security issue prior to version 0.9.0. The vulnerability arose from an incomplete allowlist in the _validate_collection_access function, which only validated ownership for collections following specific naming patterns ('user-memory-' and 'file-'). As a result, all other collection names, including the critical system-level knowledge-bases meta-collection, were not subject to ownership checks. This oversight allowed any authenticated user to access metadata information about all knowledge bases within the instance, posing a risk of unauthorized data exposure. The issue has been addressed and fixed in version 0.9.0.

Affected Version(s)

open-webui < 0.9.0

References

https://github.com/open-webui/open-webui/security/advisor...
x_refsource_CONFIRM

CVSS V3.1

Score:
4.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.