CVE-2026-12940 — CRITICAL (9.8)

Q: How severe is CVE-2026-12940?

CVE-2026-12940 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Q: Is there a patch for CVE-2026-12940?

Check the references section above for vendor advisories and patch information. Affected products include: Langflow Langflow.

Vulnerability Description

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.

CVSS Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Langflow	Langflow	>= 1.0.0, < 1.10.2

Related Weaknesses (CWE)

CWE-78

References

https://www.ibm.com/support/pages/node/7279995Vendor Advisory

FAQ

What is CVE-2026-12940?

CVE-2026-12940 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 ...

How severe is CVE-2026-12940?

CVE-2026-12940 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-12940?

Check the references section above for vendor advisories and patch information. Affected products include: Langflow Langflow.