Langflow Authenticated RCE via MCP Stdio Transport Command Injection

#!/usr/bin/env bash
# CVE-2026-105740 Checker — Langflow MCP Stdio Command Injection
# Checks installed langflow version against the fixed version (1.9.0)
# Exit codes: 1=VULNERABLE, 0=PATCHED, 2=UNKNOWN

set -euo pipefail

FIXED_VERSION="1.9.0"

version_gte() {
  # Returns 0 if $1 >= $2 using sort -V
  [ "$(printf '%s\n%s' "$1" "$2" | sort -V | head -n1)" = "$2" ]
}

# Try pip-installed langflow first
if command -v pip &>/dev/null; then
  INSTALLED=$(pip show langflow 2>/dev/null | grep -i '^Version:' | awk '{print $2}')
  if [ -n "$INSTALLED" ]; then
    echo "[*] Langflow version detected (pip): $INSTALLED"
    echo "[*] Fixed version: >= $FIXED_VERSION"
    if version_gte "$INSTALLED" "$FIXED_VERSION"; then
      echo "PATCHED — langflow $INSTALLED >= $FIXED_VERSION"
      exit 0
    else
      echo "VULNERABLE — langflow $INSTALLED < $FIXED_VERSION (CVE-2026-105740)"
      # Bonus: check auto-login config
      if [ "${LANGFLOW_AUTO_LOGIN:-}" = "true" ] || [ "${LANGFLOW_AUTO_LOGIN:-}" = "True" ]; then
        echo "WARNING — LANGFLOW_AUTO_LOGIN is True; auth barrier is effectively absent"
      fi
      exit 1
    fi
  fi
fi

# Try pip3 if pip didn't work
if command -v pip3 &>/dev/null; then
  INSTALLED=$(pip3 show langflow 2>/dev/null | grep -i '^Version:' | awk '{print $2}')
  if [ -n "$INSTALLED" ]; then
    echo "[*] Langflow version detected (pip3): $INSTALLED"
    echo "[*] Fixed version: >= $FIXED_VERSION"
    if version_gte "$INSTALLED" "$FIXED_VERSION"; then
      echo "PATCHED — langflow $INSTALLED >= $FIXED_VERSION"
      exit 0
    else
      echo "VULNERABLE — langflow $INSTALLED < $FIXED_VERSION (CVE-2026-105740)"
      exit 1
    fi
  fi
fi

# Try docker
if command -v docker &>/dev/null; then
  CONTAINERS=$(docker ps --filter "ancestor=langflowai/langflow" --format '{{.ID}} {{.Image}}' 2>/dev/null || true)
  if [ -n "$CONTAINERS" ]; then
    echo "[*] Langflow Docker container(s) detected:"
    echo "$CONTAINERS"
    echo "[!] Run this script inside each container to check version."
    echo "UNKNOWN — Docker container detected but version not checked inline"
    exit 2
  fi
fi

echo "UNKNOWN — langflow not found via pip, pip3, or Docker on this host"
exit 2