Remote Code Execution Vulnerability in IBM Langflow
CVE-2026-12940

9.8CRITICAL

Key Information:

Vendor

IBM
Status
Langflow Oss
Vendor
CVE Published:
30 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-12940?

IBM Langflow OSS versions 1.0.0 through 1.10.1 are exposed to a remote code execution vulnerability due to improper handling of environment variables in the MCP (Model Context Protocol) stdio launcher. Specifically, the vulnerability lies in the failure of the software to include critical variables like SHELLOPTS, BASHOPTS, and PS4 in its DANGEROUS_ENV_VARS blocklist, potentially allowing attackers to execute arbitrary code without authentication.

Affected Version(s)

Langflow OSS 1.0.0 <= 1.10.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-12940-Langflow-Unauth-RCE
Created by BiiTts

References

https://www.ibm.com/support/pages/node/7279995
vendor-advisorypatch

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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