CVE-2026-44555

{"id": "CVE-2026-44555", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.6, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 4.7, "exploitabilityScore": 2.8}]}, "published": "2026-05-15T20:16:46.967", "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9vvh-qmjx-p4q8", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9vvh-qmjx-p4q8", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-862"}]}], "descriptions": [{"lang": "en", "value": "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 \u2014 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."}], "lastModified": "2026-05-19T03:12:26.133", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0FB90EC3-1665-446E-AA35-4AEC207A2F3B", "versionEndExcluding": "0.9.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}