Langflow: DoS Through Lack of File Size Restriction via Deprecated Unauthenticated File Upload API
A 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.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | langflow-base | < 0.9.1 | 0.9.1 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-6596
- https://github.com/langflow-ai/langflow/commit/b5662446bc8c54d928e278d3d26ad95b62425815
- https://gist.github.com/chenhouser2025/c2aabfdee41009cfe45d28a9924742a0
- https://github.com/langflow-ai/langflow
- https://github.com/langflow-ai/langflow/commits/v1.9.1
- https://vuldb.com/submit/791919
- https://vuldb.com/vuln/358231
- https://vuldb.com/vuln/358231/cti
- https://pypi.org/project/langflow-base
- https://github.com/advisories/GHSA-vvfc-fp59-m92g
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L- Weakness (CWE)
CWE-284- Platform
- Python (PyPI)
- Package
langflow-base- Disclosed
- 20.04.2026
- Updated
- 11.10.2026 14:18
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-2572 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-vvfc-fp59-m92g - CC BY 4.0
Vulnerability history: langflow-base
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 8
- First → latest
- 04.2025 10.2026
- Without a fix
- 0
- Exploited in attacks
- 1
Severity breakdown
- Critical 2
- High 3
- Medium 3
Disclosures per year
- 2025: 2
- 2026: 6
-
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