Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint
Summary
| CVE | CVE-2026-33017 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-20 05:16:15 UTC |
| Updated | 2026-05-21 21:16:31 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 9.3 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.239810000 probability, percentile 0.961120000 (date 2026-05-27)
CISA KEV: Listed on 2026-03-25; due 2026-04-08; ransomware use Unknown
Problem Types: CWE-94 | CWE-95 | CWE-306 | CWE-94 CWE-94: Improper Control of Generation of Code ('Code Injection') | CWE-95 CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') | CWE-306 CWE-306: Missing Authentication for Critical Function
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.3 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/C... |
| 4.0 | CNA | DECLARED | 9.3 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L |
| 3.1 | [email protected] | Primary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known Exploited Vulnerability
| Vendor | Langflow |
|---|---|
| Product | Langflow |
| Name | Langflow Code Injection Vulnerability |
| Required Action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
| Notes | https://github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx ; https://nvd.nist.gov/vuln/detail/CVE-2026-33017 |
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Langflow-ai | Langflow | affected < 1.9.0 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/langflow-ai/langflow/commit/73b6612e3ef25fdae0a752d75b0fabd47... | [email protected] | github.com | Patch |
| github.com/langflow-ai/langflow/security/advisories/GHSA-vwmf-pq79-vjvx | [email protected] | github.com | Exploit, Mitigation, Vendor Advisory |
| medium.com/@aviral23/cve-2026-33017-how-i-found-an-unauthenticated-rce-i... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | medium.com | Exploit, Third Party Advisory |
| www.sysdig.com/blog/cve-2026-33017-how-attackers-compromised-langflow-ai-pip... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.sysdig.com | Press/Media Coverage |
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | US Government Resource |
| github.com/langflow-ai/langflow/releases/tag/1.8.2 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Release Notes |
| github.com/advisories/GHSA-rvqx-wpfh-mfx7 | [email protected] | github.com | Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |