Description
Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allows building public flows without requiring authentication. When the optional data parameter is supplied, the endpoint uses attacker-controlled flow data (containing arbitrary Python code in node definitions) instead of the stored flow data from the database. This code is passed to exec() with zero sandboxing, resulting in unauthenticated remote code execution. This is distinct from CVE-2025-3248, which fixed /api/v1/validate/code by adding authentication. The build_public_tmp endpoint is designed to be unauthenticated (for public flows) but incorrectly accepts attacker-supplied flow data containing arbitrary executable code. This issue has been fixed in version 1.9.0.
CISA Known Exploited Vulnerability
Date added 2026-03-25 | Due date 2026-04-08
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Problem types
CWE-94: Improper Control of Generation of Code ('Code Injection')
CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
CWE-306: Missing Authentication for Critical Function
Product status
References
www.sysdig.com/...promised-langflow-ai-pipelines-in-20-hours
medium.com/...-by-reading-the-code-they-already-dc96cdce5896
www.cisa.gov/...erabilities-catalog?field_cve=CVE-2026-33017
github.com/langflow-ai/langflow/releases/tag/1.8.2
github.com/...ngflow/security/advisories/GHSA-vwmf-pq79-vjvx
github.com/...ommit/73b6612e3ef25fdae0a752d75b0fabd47328d4f0
github.com/advisories/GHSA-rvqx-wpfh-mfx7