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CVE-2026-44555

Openwebui Open Webui broken access control

7.6 HIGHPublic exploitEPSS 0.35%
  1. Published15 May 2026

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI supports model composition via base_model_id: a user-defined model (e.g., "Cheap Assistant") can reference an existing base model (e.g., "gpt-4-turbo-restricted") that provides the actual inference capability. When a user queries the composed model, the access control pipeline verifies the user has access to the composed model but never re-verifies access to the chained base model. Additionally, the model creation and import endpoints accept arbitrary base_model_id values without checking that the caller has access to that base model. Combined, this allows any user with the default model creation permission to create a model that chains to a restricted base model — and then invoke it, causing the server to dispatch the request to the restricted base model using the admin-configured API key. This vulnerability is fixed in 0.9.0.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityLow
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L

Affected products

Openwebui Open Webui< 0.9.0

Remediation

Fixed in
Openwebui Open Webui≥ 0.9.0

Frequently asked

Is CVE-2026-44555 being actively exploited?

CVE-2026-44555 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.35%.

How severe is CVE-2026-44555?

CVE-2026-44555 has a CVSS 3.1 base score of 7.6, rated high. EPSS estimates a 0.35% probability of exploitation.

Which products are affected by CVE-2026-44555?

Affected products include Openwebui Open Webui.

How do I fix CVE-2026-44555?

Upgrade affected software to a fixed version, for example Openwebui Open Webui 0.9.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-44555 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.