{"data":{"id":"0b59d05e-70b2-46e6-9c00-c6c066a70fda","title":"GHSA-26g9-27vm-x3q8: Open WebUI: shared-chat branch ignores access_type, allowing unauthorized file deletion","summary":"Any authenticated Open WebUI user can permanently delete files owned by other users through DELETE /api/v1/files/{id} when the file is referenced in any shared chat. The has_access_to_file() function in backend/open_webui/routers/files.py grants access through its shared-chat branch without checking the requesting user's identity or the access_type operation. File UUIDs are exposed to users with read access to a knowledge base via GET /api/v1/knowledge/{id}/files, and the flaw was tested on version 0.8.3.","solution":"Suggested fix: gate the shared-chat branch on access_type so it only authorizes read operations, by checking if access_type == \"read\" before returning True when shared chats reference the file.","labels":["security"],"sourceUrl":"https://github.com/advisories/GHSA-26g9-27vm-x3q8","publishedAt":"2026-05-14T20:28:34.000Z","cveId":"CVE-2026-45671","cweIds":null,"cvssScore":null,"cvssSeverity":"high","severity":"high","attackType":["other"],"issueType":"vulnerability","affectedPackages":["open-webui@<= 0.8.12 (fixed: 0.9.0)"],"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":"2026-10-14T18:05:59.791Z","kevDateAdded":null,"advisoryAliases":["GHSA-26g9-27vm-x3q8"],"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":true,"disclosureDate":"2026-05-14T20:28:34.000Z","capecIds":null,"crossRefCount":0,"attackSophistication":"trivial","impactType":["integrity","availability"],"aiComponentTargeted":"plugin","llmSpecific":false,"classifierConfidence":0.85,"researchCategory":null,"atlasIds":null}}