Vulnerability · Published Jul 30, 2026 · Assigned by ibm

CVE-2026-12940Langflow is affected by remote code execution due to multiple unauthenticated and insufficiently authorized API endpoints

Critical 9.8

In plain English

A critical-severity OS command injection in Langflow OSS from IBM. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.9%top 38.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack tooling1Public PoC

Official 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.

Affected products (as reported)

Vendor	Product	Versions
IBM	Langflow OSS	1.0.0 – through 1.10.1

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://www.ibm.com/support/pages/node/7279995 vendor-advisory, patch