create-mastra@1.29.0

Create Mastra apps with one command

AI Security Review

scanned 1mo ago · by lpm-firewall-ai

No lifecycle abuse, hidden payload, or credential theft was established. The default, unattended modification of detected AI-agent skill surfaces is a concrete extension-lifecycle risk that warrants a warning.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

A user runs create-mastra; skills installation is enabled by default.

Impact

May alter local AI-agent skill configuration and disclose identifiable CLI telemetry.

Mechanism

PATH-based agent detection followed by an unattended skills installer command.

AI rationale

Evidence

dist/index.js~/.mastra/analytics.json~/.mastra/credentials.jsongenerated project/.env

Network endpoints2

us.posthog.complatform.mastra.ai

Decision evidence

public snapshot

AI called this Suspicious at 90.0% confidence as Dangerous Capability with low false-positive risk.

Evidence for warning

The scaffold command defaults skills installation to enabled.
It runs an unattended npx command that adds Mastra skills for detected coding agents.
It detects executables for Codex, Claude, Cursor, Gemini, and other agents from PATH.
The CLI enables telemetry by default and sends a persistent machine hostname with command metadata to PostHog.

Evidence against

package.json has no preinstall, install, or postinstall hook.
The behavior is reachable only when the user runs the create-mastra CLI.
The agent setup names the Mastra-owned skills repository directly; no hidden payload or credential exfiltration was found.
API-key entry is explicitly prompted and is written to the generated project's local .env file.

Behavioral surface

Source

ChildProcessCryptoEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsTelemetry

Source & flagged code

9 flagged

dist/index.jsView file

Lines 1-31javascript

1#! /usr/bin/env node

2import { InvalidArgumentError, Command } from 'commander';

3import { randomBytes, randomUUID } from 'node:crypto';

4import fs, { readFileSync, statSync, appendFileSync, writeFileSync, createWriteStream, createReadStream, existsSync, mkdirSync, constants as constants$2 } from 'node:fs';

5import os, { homedir, release, constants as constants$1 } from 'node:os';

6import path, { join, dirname } from 'node:path';

7import * as fsPromises from 'node:fs/promises';

8import fsPromises__default, { readFile, mkdir, writeFile, chmod } from 'node:fs/promises';

9import require$$0, { execFileSync, ChildProcess, execFile, spawnSync, spawn } from 'node:child_process';

10import { createServer } from 'node:http';

High

Child Process

Package source references child process execution.

dist/index.jsView on unpkg · L8

11import require$$4, { styleText, debuglog, stripVTControlCharacters, inspect, promisify, callbackify, aborted } from 'node:util';

12import process$2, { stdout, stdin, platform, hrtime, execPath, execArgv } from 'node:process';

13import * as l from 'node:readline';

Critical

Hardcoded Runtime Data Exfiltration

Source sends credentials or rich application records to a package-controlled external receiver enabled by default.

dist/index.jsView on unpkg · L8

Critical

Trigger Reachable Dangerous Capability

A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.

dist/index.jsView on unpkg · L8

High

Shell

Package source references shell execution.

dist/index.jsView on unpkg · L11

High

Sandbox Evasion Gated Capability

Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.

dist/index.jsView on unpkg · L8

14import l__default from 'node:readline';

15import tty, { ReadStream } from 'node:tty';

16import { PostHog } from 'posthog-node';

17import { fileURLToPath } from 'node:url';

18import { StringDecoder } from 'node:string_decoder';

19import { setTimeout as setTimeout$1, scheduler, setImmediate } from 'node:timers/promises';

20import { once, addAbortListener, EventEmitter, on, setMaxListeners } from 'node:events';

21import { serialize } from 'node:v8';

22import { Transform, getDefaultHighWaterMark, Duplex, Writable, Readable, PassThrough } from 'node:stream';

23import { Buffer as Buffer$1 } from 'node:buffer';

24import { finished } from 'node:stream/promises';

25import { x } from 'tinyexec';

27const PATH_PARAM_RE = /\{[^{}]+\}/g;

28const supportsRequestInitExt = () => {

29 return typeof process === "object" && Number.parseInt(process?.versions?.node?.substring(0, 2)) >= 18 && process.versions.undici;

30};

31function randomID() {

Lines 10317-10357javascript

10317// Wraps `finished(stream)` to handle the following case:

10318// - When the subprocess exits, Node.js automatically calls `subprocess.stdin.destroy()`, which we need to ignore.

10319// - However, we still need to throw if `subprocess.stdin.destroy()` is called before subprocess exit.

10320const waitForStream = async (stream, fdNumber, streamInfo, {isSameDirection, stopOnExit = false

Lines 15225-15265javascript

15225 });

15226 } catch (gitError) {

15227 if (signal?.aborted) signal.throwIfAborted();

15228 throw new Error(`Failed to clone repository: ${gitError instanceof Error ? gitError.

•Manifest-reachable source captures an API credential, sends it to a fixed unofficial gateway, and persists that redirection in agent or shell configuration. dist/index.js: import fs, { readFileSync, statSync, appendFileSync, writeFileSync, createWriteStream, createReadStream, existsSync, mkdirSync, constants as constants$2 } from 'node:fs'; import fsPromises__default, { readFile, mkdir, writeFile, chmod } from 'node:fs/promises'; import * as l from 'node:readline'; import l__default from 'node:readline'; baseUrl = "", baseUrl = removeTrailingSlash(baseUrl); baseUrl: localBaseUrl, let finalBaseUrl = baseUrl;

High

Credential Redirect Persistence

Manifest-reachable source sends a prompted API credential to a fixed unofficial gateway and persists the redirection.

dist/index.jsView on unpkg

Source & flagged code

9 flagged · loading source

dist/index.jsView file

8import fsPromises__default, { readFile, mkdir, writeFile, chmod } from 'node:fs/promises'; L9: import require$$0, { execFileSync, ChildProcess, execFile, spawnSync, spawn } from 'node:child_process'; L10: import { createServer } from 'node:http'; L11: import require$$4, { styleText, debuglog, stripVTControlCharacters, inspect, promisify, callbackify, aborted } from 'node:util'; L12: import process$2, { stdout, stdin, platform, hrtime, execPath, execArgv } from 'node:process'; L13: import * as l from 'node:readline'; ... L86: // with no body, we should not to set Content-Type L87: serializedBody === void 0 || // if serialized body is FormData; browser will correctly set Content-Type & boundary expression L88: serializedBody instanceof FormData ? {} : { ... L214: if (parseAs === "json" &

Critical

Hardcoded Runtime Data Exfiltration

Source sends credentials or rich application records to a package-controlled external receiver enabled by default.

dist/index.jsView on unpkg · L8

8Trigger-reachable chain: manifest.main -> dist/index.js L8: import fsPromises__default, { readFile, mkdir, writeFile, chmod } from 'node:fs/promises'; L9: import require$$0, { execFileSync, ChildProcess, execFile, spawnSync, spawn } from 'node:child_process'; L10: import { createServer } from 'node:http'; L11: import require$$4, { styleText, debuglog, stripVTControlCharacters, inspect, promisify, callbackify, aborted } from 'node:util'; L12: import process$2, { stdout, stdin, platform, hrtime, execPath, execArgv } from 'node:process'; L13: import * as l from 'node:readline'; ... L86: // with no body, we should not to set Content-Type L87: serializedBody === void 0 || // if serialized body is FormData; browser will correctly set Content-Type & boundary expression L88: serializedBody instanc

Findings

2 Critical7 High3 Medium5 Low

CriticalHardcoded Runtime Data Exfiltrationdist/index.js

CriticalTrigger Reachable Dangerous Capabilitydist/index.js

HighChild Processdist/index.js

HighShelldist/index.js

HighSame File Env Network Executiondist/index.js

HighCredential Redirect Persistencedist/index.js

HighCommand Output Exfiltrationdist/index.js

HighSandbox Evasion Gated Capabilitydist/index.js

HighTrigger Reachable Command Output Exfiltrationdist/index.js

MediumNetwork

MediumEnvironment Vars

MediumStructural Risk Force Deep Review

LowScripts Present

Affected versions and remediation

This report applies to create-mastra@1.29.0.

See all versions of create-mastra for other recorded verdicts.

Review the evidence and your use of create-mastra@1.29.0 before allowing it. Restrict the permissions described in this report.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.

Evidence last updated: 2026-09-12 00:38:25.379Z (UTC).

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AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Runtime surface

Behavioral surface

Source & flagged code