Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the restriction entirely — the request is authenticated, the model is invoked, and a full response is returned. This vulnerability is fixed in 0.9.0.
History

Tue, 19 May 2026 03:15:00 +0000

Type Values Removed Values Added
First Time appeared Openwebui
Openwebui open Webui
CPEs cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*
Vendors & Products Openwebui
Openwebui open Webui

Mon, 18 May 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 15 May 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Open-webui
Open-webui open-webui
Vendors & Products Open-webui
Open-webui open-webui

Fri, 15 May 2026 19:30:00 +0000

Type Values Removed Values Added
Description Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the restriction entirely — the request is authenticated, the model is invoked, and a full response is returned. This vulnerability is fixed in 0.9.0.
Title Open WebUI: API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-05-15T19:21:26.401Z

Updated: 2026-05-19T03:55:42.745Z

Reserved: 2026-05-11T21:40:08.176Z

Link: CVE-2026-45339

cve-icon Vulnrichment

Updated: 2026-05-18T14:30:21.256Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-15T20:16:48.693

Modified: 2026-05-19T03:07:48.750

Link: CVE-2026-45339

cve-icon Redhat

No data.