CVE-2026-45339

Open WebUI: API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints

Published May 15, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-57q6-fvp4-pqmm Open WebUI's API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints
History
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
Type Values Removed Values Added
Metrics ssvc

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

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 19, 2026, 3:55 AM
Reserved
May 11, 2026, 9:40 PM
Status
Analyzed
Published
May 15, 2026, 8:16 PM
Modified
Nov 11, 2026, 8:10 PM