CVE-2026-33017Known exploitationPublic exploitNetwork attack vector

Unauthenticated code execution via public flow data

Published Mar 20, 2026 · Updated Mar 20, 2026

Code injection in Langflow OSS before 1.9.0 allows remote attackers to execute arbitrary Python through a public flow build request. The unauthenticated POST /api/v1/build_public_tmp/{flow_id}/flow handler accepts a caller-supplied data graph, extracts node code, and sends compiled definitions to exec() without sandboxing. A known public-flow UUID and any client_id cookie are sufficient; default AUTO_LOGIN also lets remote attackers create the required public flow and compromise the server process.

CVSS severity9.3
Critical
EPSS probability96.18%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Langflow OSS before 1.9.0 allows remote attackers to execute arbitrary Python through a public flow build request. The unauthenticated POST /api/v1/build_public_tmp/{flow_id}/flow handler accepts a caller-supplied data graph, extracts node code, and sends compiled definitions to exec() without sandboxing. A known public-flow UUID and any client_id cookie are sufficient; default AUTO_LOGIN also lets remote attackers create the required public flow and compromise the server process.

The record

CVE
CVE-2026-33017
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
OpenBMC Project
Product
Langflow OSS
Classifications
CWE-95, CWE-94, CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenBMC Project · Langflow OSSversion=< 1.9.0

Published CVSS scores

9.3GitHub, Inc.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
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-95Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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