Improper Input Validation in Open WebUI's API Allows Unauthorized File Access
CVE-2026-54009

6.5MEDIUM

Key Information:

Vendor

Open-webui

Status
Open-webui
Vendor
CVE Published:
23 June 2026

What is CVE-2026-54009?

Open WebUI, a self-hosted AI platform, has a vulnerability in its API that allows authenticated users to exploit improperly validated input in the POST /api/chat/completions endpoint. When an image_url.url value does not conform to expected protocols (http, https, or data:image/), it is treated as a file ID without proper ownership verification. This flaw enables an attacker to access another user's files by manipulating the image_url.url parameter, resulting in the server reading the unauthorized file and processing its content. The issue has been addressed in version 0.9.6.

Affected Version(s)

open-webui < 0.9.6

References

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

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.