Unauth RCE in IBM Langflow OSS 1.0.0-1.10.1 via env var injection
CVE-2026-12940 Published on July 30, 2026
Langflow is affected by remote code execution due to multiple unauthenticated and insufficiently authorized API endpoints
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.
Vulnerability Analysis
CVE-2026-12940 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
What is a Shell injection Vulnerability?
The software constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
CVE-2026-12940 has been classified to as a Shell injection vulnerability or weakness.
Products Associated with CVE-2026-12940
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Affected Versions
IBM Langflow OSS:- Version 1.0.0, <= 1.10.1 is affected.