CVE-2026-12940: Langflow

Critical severity, CVSS 9.8. EPSS: 0.9% chance of exploitation in the next 30 days.

IBM Langflow OSS 1.0.0 through 1.10.1  are vulnerable to unauthenticated remote code execution via environment variable injection in the MCP (Model Context Protocol) stdio launcher. The vulnerability exists in src/lfx/src/lfx/base/mcp/util.py where the DANGEROUS_ENV_VARS blocklist fails to include SHELLOPTS , BASHOPTS , and PS4 environment variables.

Affected products

• Langflow Langflow: from 1.0.0, before 1.10.2 (fixed in 1.10.2)

Published 2026-07-30. Last modified 2026-08-04.