{"cve":"CVE-2026-44556","nvd":{"published":"2026-05-15T20:16:47.097","modified":"2026-06-17T10:50:47.223","status":"Analyzed","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. 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H","score":7.1},"cwes":["CWE-284","CWE-862"],"references":["https://github.com/open-webui/open-webui/security/advisories/GHSA-hp5m-24vp-vq2q"],"products":["openwebui:open_webui"],"source":"nvd","synced_at":"2026-10-19T22:35:16.954578616+00:00"},"epss":{"cve":"CVE-2026-44556","score":0.00306,"percentile":0.23457,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-hp5m-24vp-vq2q","url":"https://osv.dev/vulnerability/GHSA-hp5m-24vp-vq2q","summary":"Open WebUI's responses passthrough endpoint lacks access control authorization","modified":"2026-07-13T16:43:17.785826482Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.9.0"],"fixed":["0.9.0"]}]},{"id":"PYSEC-2026-2734","url":"https://osv.dev/vulnerability/PYSEC-2026-2734","summary":"Open WebUI's responses passthrough endpoint lacks access control authorization","modified":"2026-07-13T16:32:15.744053190Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.9.0"],"fixed":["0.9.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}