CVE-2026-45339
Open WebUI: API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-863 |
| Vendor | open-webui |
| Product | open-webui |
| Published | May 15, 2026 |
Stay Ahead of the Next One
Get instant alerts for open-webui open-webui
Be the first to know when new medium vulnerabilities affecting open-webui open-webui are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
open-webui / open-webui
< 0.9.0