Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint

Summary

CVECVE-2026-33017
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-03-20 05:16:15 UTC
Updated2026-05-21 21:16:31 UTC
DescriptionLangflow 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


VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary9.3CRITICALCVSS: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...
4.0CNADECLARED9.3CRITICALCVSS: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]Primary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
Low
Sub Integrity
Low
Sub Availability
Low

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

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA Known Exploited Vulnerability

VendorLangflow
ProductLangflow
NameLangflow Code Injection Vulnerability
Required ActionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Noteshttps://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)

TypeVendorProductVersionUpdateEditionLanguage
Application Langflow Langflow All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Langflow-ai Langflow affected < 1.9.0 Not specified

References

ReferenceSourceLinkTags
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
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