Unauthenticated RCE in Langflow Hit by Rapid Exploitation Attempts
Active Exploitation · 2 sources · Updated 3mo ago · First seen Apr 10, 2025
A critical vulnerability in the LangChain-based no-code LLM development platform Langflow exposed internet-facing instances to unauthenticated remote code execution. Tracked as CVE-2025-3248 and rated CVSS 9.8, the flaw was disclosed after researchers showed that unsafe use of Python exec could be abused through Langflow's code-validation functionality, allowing attackers to run arbitrary Python on vulnerable servers.
Security monitoring by MBSD-SOC found exploitation attempts beginning on April 10, 2025, shortly after public disclosure on April 8. Attackers were observed sending crafted POST requests to the /api/v1/validate/code endpoint to execute malicious Python, including attempts to read sensitive files such as /etc/passwd. The report said proof-of-concept code and real-world abuse were already circulating, and urged organizations to update Langflow immediately; telemetry cited the Netherlands and France as the source of roughly half of observed attack traffic.
