Cyber Posture

CVE-2026-44556

High

Published: 15 May 2026

Published
15 May 2026
Modified
15 May 2026
KEV Added
Patch
CVSS Score 7.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
EPSS Score 0.0003 10.4th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-44556 is a high-severity Improper Access Control (CWE-284) vulnerability. Its CVSS base score is 7.1 (High).

Operationally, ranked at the 10.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-284 CWE-862

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284 CWE-862

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284 CWE-862

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284 CWE-862

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284 CWE-862

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284 CWE-862

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

addresses: CWE-284 CWE-862

Requiring authorization and configuration controls for mobile device connections directly enforces access control and prevents unauthorized devices from reaching organizational systems.

addresses: CWE-284 CWE-862

Defining account types, requiring approvals for creation, specifying authorizations, monitoring usage, and reviewing accounts directly prevents improper access control by ensuring only authorized accounts exist and are used.

NVD Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the /responses endpoint in the OpenAI router accepts any authenticated user and forwards requests directly to upstream LLM providers without enforcing per-model access control.…

more

While the primary chat completion endpoint (generate_chat_completion) checks model ownership, group membership, and AccessGrants before allowing a request, the /responses proxy only validates that the user has a valid session via get_verified_user. This allows any authenticated user to interact with any model configured on the instance by sending a POST request to /api/openai/responses with an arbitrary model ID. This vulnerability is fixed in 0.9.0.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)

References