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CVE-2026-33017: Langflow Code Injection Vulnerability
CVE-2026-33017: critical vulnerability affecting Langflow. Check CVSS, KEV status, business impact and recommended administrator actions.
- CVSS
- 9.3 CRITICAL
- EPSS
- 99.91%
- Known exploited
- yes
- Product
- Langflow
What is known
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.
Business impact
Successful exploitation of CVE-2026-33017, a critical vulnerability (CVSS 9.3) affecting Langflow, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration. CISA lists this vulnerability in the Known Exploited Vulnerabilities catalog, so exposed systems should be treated as a priority.
Recommended administrator action
Confirm whether Langflow is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. Where applicable, include the CISA KEV remediation due date of 2026-04-08 in the change plan. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.