{"data":{"id":"11613dd4-9487-4828-bb68-4b0e0798b88a","title":"GHSA-r472-mw7m-967f: Open WebUI: Cross-User File Access via Unchecked file_id in Folder Knowledge and Knowledge-Base Attach Endpoints","summary":"Multiple Open WebUI endpoints accept a user-supplied `file_id` and attach that file to a resource the caller controls without checking the caller's access to the file. Path 1 is `POST /api/v1/folders/{id}/update` through the folder knowledge consumer in `backend/open_webui/utils/middleware.py`, where the referenced file becomes RAG context for chat completions. Path 2 is the knowledge-base attach endpoints in `backend/open_webui/routers/knowledge.py`, which grant read and write access to the file through `/api/v1/files/{id}/content` and `/api/v1/files/{id}/data/content/update`. An authenticated user who knows another user's file UUID can exfiltrate that file, and on Path 2 also overwrite it.","solution":"N/A -- no mitigation discussed in source.","labels":["security"],"sourceUrl":"https://github.com/advisories/GHSA-r472-mw7m-967f","publishedAt":"2026-05-14T20:27:35.000Z","cveId":"CVE-2026-45402","cweIds":null,"cvssScore":null,"cvssSeverity":"high","severity":"high","attackType":["other"],"issueType":"vulnerability","affectedPackages":["open-webui@<= 0.9.4 (fixed: 0.9.5)"],"affectedPackageNames":["open-webui"],"affectedPackageRefs":["pypi:open-webui"],"affectedVendors":[],"affectedVendorsRaw":["Open WebUI"],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":null,"headlinePromptVersion":null,"cvssVector":null,"attackVector":null,"attackComplexity":null,"privilegesRequired":null,"userInteraction":null,"exploitMaturity":"unknown","epssScore":0.00393,"epssCheckedAt":"2026-10-14T18:05:59.956Z","kevDateAdded":null,"advisoryAliases":["GHSA-r472-mw7m-967f"],"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":true,"disclosureDate":"2026-05-14T20:27:35.000Z","capecIds":null,"crossRefCount":0,"attackSophistication":"trivial","impactType":["confidentiality","integrity"],"aiComponentTargeted":"rag","llmSpecific":false,"classifierConfidence":0.95,"researchCategory":null,"atlasIds":null}}