CVE•Published 2026-07-30•Modified 2026-08-04•1 article on news•6 live references•NVD data

CVE-2026-12940Langflow · Langflow

Vulnerability data via NVD (ingested)

CVSS v3.1

9.8

CRITICAL

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

EPSS percentile

Exploit Prediction Scoring System · top 61% of all CVEs

Weaknesses (CWE)

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

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.

Timeline

Published 2026-07-30

Modified 2026-08-04

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common). Live host counts are a Premium feature.

Shodan · vuln tag

vuln:CVE-2026-12940

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Langflow Langflow"

All exposed Langflow Langflow instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Langflow"

HTTP body or banner mentions "Langflow" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-12940