{"data":{"id":"af75fe66-33f5-4086-b3d6-69fcdb3c7052","title":"GHSA-x223-p2gf-v735: Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak","summary":"Langflow's deprecated POST /api/v1/upload/{flow_id} endpoint in langflow/api/v1/endpoints.py had no authentication and no validation of flow_id, so unauthenticated users with network access could upload unlimited data. The upload wrote to local disk, enabling space exhaustion and denial of service, and the response disclosed the absolute server path of the uploaded file, an information leak. The issue was tested on commit 2d67402b1dbaefcbce85a244d4a6cd5e4bda1cfe.","solution":"Fixed in 1.9.1 via PR #12831. The endpoint now uses the get_flow dependency, requiring an authenticated user and flow ownership, and enforces the max_file_size_upload limit (HTTP 413). Upgrade to 1.9.1 or later. The response still returns file_path, but only to the authenticated flow owner.","labels":["security"],"sourceUrl":"https://github.com/advisories/GHSA-x223-p2gf-v735","publishedAt":"2026-06-17T18:43:12.000Z","cveId":"CVE-2026-55450","cweIds":null,"cvssScore":null,"cvssSeverity":"critical","severity":"critical","attackType":["denial_of_service","other"],"issueType":"vulnerability","affectedPackages":["langflow@< 1.9.1 (fixed: 1.9.1)"],"affectedPackageNames":["langflow"],"affectedPackageRefs":["pypi:langflow"],"affectedVendors":[],"affectedVendorsRaw":["Langflow"],"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":0.0119,"epssCheckedAt":"2026-11-04T12:08:35.257Z","kevDateAdded":null,"advisoryAliases":["GHSA-x223-p2gf-v735"],"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":true,"disclosureDate":"2026-06-17T18:43:12.000Z","fixReleasedAt":"2026-04-24T00:34:19.524Z","daysToFix":-54,"fixCheckedAt":"2026-10-29T21:34:20.923Z","capecIds":null,"crossRefCount":0,"attackSophistication":"trivial","impactType":["availability","confidentiality"],"aiComponentTargeted":"api","llmSpecific":false,"classifierConfidence":0.9,"researchCategory":null,"atlasIds":null,"fixes":[{"ecosystem":"pypi","name":"langflow","fixedVersion":"1.9.1","matchedVersion":"1.9.1","fixReleasedAt":"2026-04-24T00:34:19.524Z","daysToFix":-54,"match":"ecosystem","source":"tracked","status":"found","checkedAt":"2026-10-29T21:34:20.777Z"}]}}