CVE-2026-44556Network attack vector

Authenticated model access bypass via unchecked responses proxy

Published May 15, 2026 · Updated May 15, 2026

Missing authorization in Open WebUI before 0.9.0 allows remote authenticated users to access restricted models over the network. The /api/openai/responses proxy accepts an arbitrary model ID after only get_verified_user session validation, omitting the ownership, group, and AccessGrant checks used by generate_chat_completion. Any valid account can consume restricted upstream models and exhaust shared API budgets or rate limits, but the endpoint does not directly expose workspace-specific data.

CVSS severity7.1
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing authorization in Open WebUI before 0.9.0 allows remote authenticated users to access restricted models over the network. The /api/openai/responses proxy accepts an arbitrary model ID after only get_verified_user session validation, omitting the ownership, group, and AccessGrant checks used by generate_chat_completion. Any valid account can consume restricted upstream models and exhaust shared API budgets or rate limits, but the endpoint does not directly expose workspace-specific data.

The record

CVE
CVE-2026-44556
Published
May 15, 2026
Updated
May 15, 2026
Vendor
Open WebUI
Product
Open WebUI
Classifications
CWE-862, CWE-284
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 15, 2026CVE publishedPublication date reported by the CVE source.
  2. May 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Open WebUI · Open WebUIversion=< 0.9.0

Published CVSS scores

7.1GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-284Improper Access Control

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo