What is CVE-2026-12940?

CVE-2026-12940 is a critical-severity vulnerability in Ibm Langflow Oss, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-07-30.

How severe is CVE-2026-12940?

Critical severity. CVSS v3 base score is 9.8 out of 10.

RCE in Ibm Langflow Oss

CVE-2026-12940

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…

Vulnerability class: Command Injection (OS Command Injection)

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Ibm Langflow Oss — versions 1.0.0

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

psirt@us.ibm.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-12940?: CVE-2026-12940 is a critical-severity vulnerability in Ibm Langflow Oss, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-07-30.
How severe is CVE-2026-12940?: Critical severity. CVSS v3 base score is 9.8 out of 10.