CVE-2026-33017: Langflow Unauthenticated Remote Code Execution via Public Flow Build Endpoint
Summary
CVE-2026-33017: Unauthenticated Remote Code Execution in Langflow via Public Flow Build Endpoint. Affects langflow versions < 1.8.1. No fix is published. How to fix ↓
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Background
Langflow is an open-source framework designed for building and managing workflows, particularly in the context of chatbots and data processing. It allows users to create flows that can be executed without requiring extensive programming knowledge. However, the framework has a critical vulnerability that exposes it to unauthenticated remote code execution, allowing attackers to exploit public flows without any authentication.
Vulnerability Detail
The vulnerability exists in the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint, which is intended to allow unauthenticated users to build public flows. When the attacker supplies the optional 'data' parameter, it can contain arbitrary Python code. This code is executed using the exec() function without any sandboxing, leading to remote code execution on the server. The implications of this vulnerability are severe, as it allows attackers to execute arbitrary commands, potentially compromising the entire server and accessing sensitive information.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, avoid using the build_public_tmp endpoint until the vulnerability is patched. Ensure that public flows do not accept any user-supplied data that could lead to code execution.
Conclusion
CVE-2026-33017 is a critical vulnerability in Langflow that allows unauthenticated remote code execution through a public flow build endpoint. It is essential for users to update to the patched version or implement workarounds to mitigate the risk of exploitation.
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FAQ
CVE-2026-33017 is a critical vulnerability in Langflow that allows unauthenticated remote code execution through the public flow build endpoint.
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The vulnerability can lead to complete server compromise, allowing attackers to execute arbitrary commands, read/write files, and exfiltrate sensitive data.
Yes, a patch is available in version 1.8.2 of Langflow. Users should update to this version to mitigate the vulnerability.
If immediate updates are not possible, avoid using the vulnerable endpoint and ensure that no user-supplied data is processed by the application.
References
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