{"cve":"CVE-2026-45402","nvd":{"published":"2026-05-15T21:16:38.273","modified":"2026-06-17T10:52:01.363","status":"Analyzed","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, multiple endpoints accept a user-supplied file_id and attach the referenced file to a resource the caller controls (folder knowledge, knowledge-base contents) without verifying that the caller owns or has been granted access to the file. The file's content then becomes reachable through the downstream RAG / file-content paths, allowing any authenticated user to exfiltrate any other user's private file — and on the knowledge-base path, also to overwrite it — given knowledge of the file's UUID. This affects backend/open_webui/routers/folders.py (POST /api/v1/folders/{id}/update), backend/open_webui/routers/knowledge.py (add_file_to_knowledge_by_id), and backend/open_webui/routers/knowledge.py (add_files_to_knowledge_by_id_batch). This vulnerability is fixed in 0.9.5.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","score":8.1},"cwes":["CWE-639"],"references":["https://github.com/open-webui/open-webui/security/advisories/GHSA-r472-mw7m-967f","https://github.com/open-webui/open-webui/security/advisories/GHSA-r472-mw7m-967f"],"products":["openwebui:open_webui"],"source":"nvd","synced_at":"2026-10-19T22:35:16.954578616+00:00"},"epss":{"cve":"CVE-2026-45402","score":0.00346,"percentile":0.282,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-r472-mw7m-967f","url":"https://osv.dev/vulnerability/GHSA-r472-mw7m-967f","summary":"Open WebUI: Cross-User File Access via Unchecked file_id in Folder Knowledge and Knowledge-Base Attach Endpoints","modified":"2026-07-13T16:42:41.560701303Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.9.5"],"fixed":["0.9.5"]}]},{"id":"PYSEC-2026-2752","url":"https://osv.dev/vulnerability/PYSEC-2026-2752","summary":"Open WebUI: Cross-User File Access via Unchecked file_id in Folder Knowledge and Knowledge-Base Attach Endpoints","modified":"2026-07-13T16:32:21.692137399Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.9.5"],"fixed":["0.9.5"]}]}],"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."]}