VULNERABILITY INTELLIGENCE
CVE-2026-33017
Known Exploited Vulnerability
Langflow Code Injection Vulnerability
Vendor / product: Langflow / Langflow
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.
Weakness classification
- 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
Primary references
- security-advisories@github.com — Third Party Advisory
- security-advisories@github.com — Patch
- security-advisories@github.com — Exploit, Mitigation, Vendor Advisory
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Release Notes
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Third Party Advisory
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 — US Government Resource
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Press/Media Coverage