CVE-2026-6596
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA security flaw has been discovered in langflow-ai langflow up to 1.1.0. This issue affects the function create_upload_file of the file src/backend/base/Langflow/api/v1/endpoints.py of the component API Endpoint. The manipulation results in unrestricted upload. It is possible to launch the attack remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThe create_upload_file API endpoint in langflow up to version 1.1.0 lacks proper validation of uploaded files, allowing attackers to upload arbitrary file types to the server. This unrestricted file upload vulnerability can be exploited remotely and may lead to remote code execution if malicious files (e.g., web shells) are uploaded to accessible directories.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify langflow installation and versionRun 'pip show langflow' or check your package manager to determine the installed version of langflowAffected if The installed version is 1.1.0 or earlier (any version up to and including 1.1.0)
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Locate the create_upload_file API endpointCheck your langflow API configuration and routing files for the /upload/file or create_upload_file endpoint definitionAffected if The endpoint exists and is exposed without additional authentication beyond basic API access
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Identify upload directory locationReview langflow configuration files (typically config.yaml, settings.py, or environment variables) for upload_path or file_upload_dir settingsAffected if The configured upload directory is within the web root or accessible via static file serving
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Check for file type validation in upload handlerExamine the source code or configuration handling the create_upload_file endpoint for mime-type or extension validation logicAffected if No file type validation is implemented, or validation relies only on file extension (not magic bytes or content inspection)
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Verify uploaded files are not executableInspect the upload directory to see if uploaded files retain their original names and extensionsAffected if Uploaded files are saved with their original filenames and extensions, allowing .php, .js, or other executable extensions to be uploaded directly
You are affected if langflow version 1.1.0 or earlier is running with the upload API exposed and files are stored in web-accessible locations without content-based validation.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement strict file type validation using magic byte inspection, enforce file size limits, rename uploaded files to prevent filename-based attacks, and store uploads outside the web root with randomized filenames.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-6596 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-6596 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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