CVE-2026-33017

Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint

CVSS 4.0 Critical 9.3Known exploited (CISA KEV)

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

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.

Key data

CVSS 4.0 Critical 9.3

Score published by GitHub_M in the CVE record.

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

Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No measurable action is needed to get around the system's built-in security controls. The attack is repeatable.
Attack requirements: None
The attack works without any special deployment or execution conditions.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Vulnerable system: confidentiality: High
Serious or total effect on the secrecy of data.
Vulnerable system: integrity: High
Serious or total effect on the trustworthiness of data.
Vulnerable system: availability: High
Serious or total effect on availability.
Subsequent systems: confidentiality: Low
Limited effect on other systems' data secrecy.
Subsequent systems: integrity: Low
Limited effect on other systems' data trustworthiness.
Subsequent systems: availability: Low
Limited effect on other systems' availability.

Metric	Value	What it means
Attack vector	Network	The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity	Low	No measurable action is needed to get around the system's built-in security controls. The attack is repeatable.
Attack requirements	None	The attack works without any special deployment or execution conditions.
Privileges required	None	No account or privileges are needed.
User interaction	None	No action from any user is needed.
Vulnerable system: confidentiality	High	Serious or total effect on the secrecy of data.
Vulnerable system: integrity	High	Serious or total effect on the trustworthiness of data.
Vulnerable system: availability	High	Serious or total effect on availability.
Subsequent systems: confidentiality	Low	Limited effect on other systems' data secrecy.
Subsequent systems: integrity	Low	Limited effect on other systems' data trustworthiness.
Subsequent systems: availability	Low	Limited effect on other systems' availability.

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.

EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score: 0.96350 (96.4% probability)
Percentile: 99.9%
Scores of: Nov 10, 2026
Model: v2026.06.15

CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog: Langflow Code Injection Vulnerability
Added to the catalog: Mar 25, 2026
Federal due date: Apr 8, 2026

CISA assessment as of Mar 26, 2026

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation: Recorded by CISA as active
Automatable: yes
Technical impact: total

Weakness (CWE)

CWE catalog version 5.0.

CWE-94Improper Control of Generation of Code
CWE-95Improper Neutralization of Directives in Dynamically Evaluated Code
CWE-306Missing Authentication for Critical Functionality

Affected products

Products listed in the CVE record, as the CNA published them.

langflow-ai langflow
- affected: < 1.9.0

References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

Timeline

ID reservedMar 17, 2026
Record publishedMar 20, 2026
Added to CISA KEVMar 25, 2026
Record last updatedMay 21, 2026

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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:12 UTC. Sources and licenses