Threat actors have started exploiting a critical-severity remote code execution (RCE) vulnerability in the AI low-code platform Langflow, vulnerability intelligence firm VulnCheck warns.

Tracked as CVE-2026-0768 (CVSS score of 9.8), the security defect exists within the code validator in Langflow’s custom component editor.

Because a user-supplied string is not properly validated before it is used for Python code execution, an attacker could exploit the bug to execute arbitrary code as root without authentication.

The security flaw was reported through ZDI in July 2025 and was publicly disclosed as a zero-day in January 2026. All Langflow releases up to version 1.4.2 are affected.

According to VulnCheck, threat actors have been exploiting the vulnerability to perform reconnaissance and credential harvesting operations.