Langflow Code Injection Vulnerability

Added to KEV
2026-03-25
Federal due date
2026-04-08
Vendor
Langflow
Product
Langflow
EPSS
96.2th percentile (score 0.247, as of 2026-06-08)
NVD CVSS v3.1
9.8 (CRITICAL)
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2026-33017

CISA short description

Langflow contains a code injection vulnerability that could allow building public flows without requiring authentication.

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.

NVD 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.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.