registry / AI-agent capability abuse / create-mastra / 1.27.3

create-mastra@1.27.3

Create Mastra apps with one command

AI Security Review

scanned 1mo ago · by lpm-firewall-ai

This is not malicious install-hook behavior, but default remote coding-agent extension setup and host telemetry are concrete user-impacting risks. The scanner's credential-exfiltration claim is not supported by the inspected source.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

User runs create-mastra without --no-skills or telemetry opt-out.

Impact

A generated project may receive agent integrations from a remote package; host metadata is sent to PostHog.

Mechanism

Remote agent-skills installation and default telemetry collection.

AI rationale

Evidence

dist/index.js.mastra/analytics.json.env

Network endpoints1

us.posthog.com

Decision evidence

public snapshot

AI called this Suspicious at 88.0% confidence as Dangerous Capability with low false-positive risk.

Evidence for warning

The create command installs a remote Mastra skills package with npx and auto-detected coding-agent targets by default.
The CLI starts PostHog telemetry by default and sends a persistent machine identifier and system properties.
The package writes a user-supplied model API key only into the generated project's protected .env file.

Evidence against

package.json has no preinstall, install, or postinstall lifecycle hook.
The agent-skills action runs only after the user invokes the create CLI and can be disabled with --no-skills.
No source path sends prompted model API keys or command output to a non-Mastra endpoint.

Behavioral surface

Source

ChildProcessCryptoEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsTelemetryUrlStrings

ManifestNo manifest risk signals triggered.

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 15209-15249javascript

15209 });

15210 } catch (gitError) {

15211 if (signal?.aborted) signal.throwIfAborted();

15212 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@1.27.3.

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

Review the evidence and your use of create-mastra@1.27.3 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: 2026-09-13 14:18:57.275Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Runtime surface

Behavioral surface

Source & flagged code