CVE-2026-33017 Technical Vulnerability Analysis & Patch Advisory (CVSS 9.8)

Affected Vendors

security-advisory

Affected Components

enterprise-software

Published Date

2026-03-20

Executive & SecOps Summary

SECOPS ASSESSMENT

Affected Scope

Systems running unpatched versions impacted by CVE-2026-33017

Impact

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...

Mitigation

Apply vendor security patches and restrict external network exposure.

Affected Products & Version Scope

All unpatched versions listed in the official NVD CPE configurations

Remediation & Live Workaround Commands

PATCH & WORKAROUND

Remediation Steps

Upgrade to the latest patched release from the vendor.
Apply virtual patching or network segmentation until maintenance windows allow full patching.

Recommended Security Control & Mitigation Partner

Cloudflare Enterprise & Pro WAF

Reduce your attack surface immediately with automated vulnerability scanning and runtime protection.

Block Exploits Instantly with Managed Virtual Patching Rules

Can't patch production immediately? Deploy managed WAF rules at the edge to intercept RCE, SQLi, and deserialization payloads before they hit your origin server.

3-min setup · Automated Zero-Day Managed Rules

Deploy Instant WAF Protection Free

Practice Exploiting & Patching This Web Vulnerability in an Interactive Lab

Launch Hands-On Security Lab

Technical Root Cause & Exploitation Mechanics

Technical Overview

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.

CVSS Score: 9.8 (CRITICAL)
CWE IDs: CWE-94, CWE-95, CWE-306