Critical Langflow `validate_code()` RCE Added to KEV as Metasploit Module Emerges

A critical unauthenticated remote code execution flaw in Langflow, tracked as CVE-2026-0770, has been actively exploited against the platform’s /api/v1/validate/code endpoint. The vulnerability affects Langflow versions 0.0.31 through 1.7.3 and stems from unsafe use of Python’s exec() during server-side code validation, allowing attackers to submit crafted function definitions that execute arbitrary operating system commands. Reported post-exploitation activity included reconnaissance, credential theft, environment-variable collection, cloud metadata access, and retrieval of second-stage payloads.

CISA added CVE-2026-0770 to its Known Exploited Vulnerabilities catalog and directed U.S. federal civilian agencies to remediate it under BOD 26-04, while Langflow addressed the issue in its release-1.10.1 branch by replacing exec()-based validation with compile-only validation and adding regression tests. Separately, a Metasploit exploit module for the bug is under active development in the Rapid7 framework, increasing the likelihood of broader weaponization. Organizations with internet-facing Langflow deployments are being urged to patch immediately and investigate exposed systems as potentially compromised even after remediation.