registry / AI-agent control-surface risk / create-chemx / 26.9.16-1408

create-chemx@26.9.16-1408

Chemical X Protocol: Private drop-in architecture starter kit and capsule generator

AI Security Review

scanned 11d ago · by lpm-firewall-ai

The manifest-triggered postinstall path makes unconsented changes to consumer and user-level AI-agent control configuration. This meets the policy for blocking an automatic lifecycle mutation of a foreign agent control surface.

Static reason

High-risk behavior combination matched malicious policy.; previous stored version diff introduced dangerous source

Trigger

npm installation runs the package postinstall hook.

Impact

The package adds a new server to agent configuration, which can cause the agent to launch the package's MCP command in later sessions.

Mechanism

The hook calls the MCP installer for the consumer directory; the installer writes Cursor and VS Code configuration and may write the Gemini user configuration, pointing those agents to the chemx MCP command.

Policy narrative

During npm installation, the postinstall hook writes MCP configuration for the consumer's Cursor and VS Code directories and may alter the user's Gemini configuration. Those entries direct agents to run the chemx MCP command. The configuration mutation is automatic and is not guarded by the package's separate interactive installer prompt.

AI rationale

Evidence

package.jsoncli/postinstall.jscli/mcp/installer.js

Decision evidence

public snapshot

AI identified this as a dangerous AI-agent capability at 97.0% confidence with low false-positive risk.

Evidence for policy risk

package.json defines a postinstall hook that runs cli/postinstall.js.
The postinstall hook targets the consuming project and calls the MCP installer without a consent prompt.
The installer writes MCP configuration into the project's Cursor and VS Code agent directories.
When the user-level Gemini configuration directory exists, the installer also writes an MCP server entry there.
The added server entry launches the chemx MCP command, and the installer may add a chemx:mcp script to the consumer package.json.
The separate installer wizard presents an explicit choice before installing MCP configuration; that prompt does not guard the automatic postinstall path.

Evidence against

The package also offers MCP setup through a user-facing installer wizard, where the user selects whether to install it.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStrings

Source & flagged code

9 flagged

package.jsonView file

Lines 32-71json

32 ".": "./cli/index.js",

33 "./audit": "./cli/audit.js",

34 "./build": "./cli/build.js",

35 "./search": "./cli/search.js",

36 "./mcp": "./cli/mcp/index.js",

37 "./reader": "./cli/reader.js",

38 "./patcher": "./cli/patcher.js"

39 },

40 "scripts": {

41 "publish:both": "node scripts/publish-both.mjs",

42 "test": "node --test cli/audit/*.spec.js cli/mcp/*.spec.js cli/*.spec.js",

43 "typecheck": "tsc --noEmit",

44 "create-capsule": "node cli/index.js",

45 "audit": "node cli/index.js audit",

46 "ci:audit": "node cli/index.js audit --ci --dir=cli",

47 "chemx": "node cli/index.js",

48 "q": "node cli/index.js q",

49 "search": "node cli/index.js search",

50 "mcp": "node cli/index.js mcp",

51 "install-mcp": "node cli/index.js install-mcp",

52 "postinstall": "node cli/postinstall.js",

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L52

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg · L52

53 "read": "node cli/index.js read",

54 "patch": "node cli/index.js patch"

55 },

56 "dependencies": {

57 "@babel/parser": "^7.29.8",

58 "@babel/traverse": "^7.29.8",

59 "@babel/types": "^7.29.8",

60 "react": "^18.3.1",

61 "react-dom": "^18.3.1"

62 },

63 "devDependencies": {

64 "@types/babel__traverse": "^7.28.0",

65 "@types/node": "^22.20.2",

66 "@types/react": "^18.3.31",

67 "@types/react-dom": "^18.3.7",

68 "typescript": "^5.9.3"

69 }

70}

cli/audit-preflight-git.jsView file

Lines 1-21javascript

1import fs from 'node:fs';

2import { spawnSync } from 'node:child_process';

High

Child Process

Package source references child process execution.

cli/audit-preflight-git.jsView on unpkg · L1

4const SOURCE_FILE_PATTERN = /\.

cli/terminal.jsView file

Lines 1-30javascript

1import readline from "node:readline";

2import { spawnSync } from "node:child_process";

3import { formatChemicalXGradient, ANSI } from "./theme.js";

5export const openBrowser

cli/license.jsView file

Lines 1-23javascript

1import fs from 'node:fs';

2import path from 'node:path';

3import os from 'node:os';

4import { spawnSync } from 'node:child_process';

cli/mcp/installer.jsView file

Lines 1-21javascript

1import fs from 'node:fs';

2import path from 'node:path';

3import os from 'node:os';

5const SERVER_KEY =

cli/scaffold.jsView file

•Manifest-trigger-reachable source links an external AI-agent control path to a behavior-bearing write operation. import fs from 'node:fs'; import path from 'node:path'; import { hasgum, guminput, promptquestion, renderbanner } from './terminal.js'; import { obtainlicensekey, fetchstarterkitfiles, loadlocalblueprintfiles } from './license.js'; export const runscaffold = async (projectname, rawargs = [], onrunaudit = null) => { renderbanner('chemical x: molecular architecture scaffolder (npm create chemx)'); const licensekey = await obtainlicensekey(rawargs, onrunaudit); let iscommunity = false; let files = {}; if (!licensekey) { process.stdout.write( '\n\x1b[38;2;98;201;255m⚡ chemical x: community edition (free)\x1b[0m\n' + 'the community version is free because

High

Trigger Reachable External Ai Agent Control Surface Mutation

Manifest-trigger-reachable source writes behavior-bearing configuration into a user or project AI-agent control surface.

cli/scaffold.jsView on unpkg

scripts/pre-commit.shView file

•matchType = previous_version_dangerous_delta matchedPackage = create-chemx@26.9.14-1358 matchedIdentity = npm:Y3JlYXRlLWNoZW14:26.9.14-1358 similarity = 0.786 summary = stored previous version shares package body but lacks this dangerous source file

High

Previous Version Dangerous Delta

This package version adds a dangerous source file absent from the previous stored version; route for source-aware review.

scripts/pre-commit.shView on unpkg

•path = scripts/pre-commit.sh kind = build_helper sizeBytes = 4608 magicHex = [redacted]

Medium

Ships Build Helper

Package ships non-JavaScript build or shell helper files.

scripts/pre-commit.shView on unpkg

Source & flagged code

9 flagged · loading source

package.jsonView file

•scripts.postinstall = node cli/postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node cli/postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

cli/audit-preflight-git.jsView file

1import fs from 'node:fs'; L2: import { spawnSync } from 'node:child_process'; L3:

High

Child Process

Package source references child process execution.

cli/audit-preflight-git.jsView on unpkg · L1

Findings

1 Critical6 High5 Medium4 Low

CriticalAi Agent Control Hijackcli/mcp/installer.js

HighInstall Time Lifecycle Scriptspackage.json

HighChild Processcli/audit-preflight-git.js

HighShellcli/terminal.js

HighSame File Env Network Executioncli/license.js

HighTrigger Reachable External Ai Agent Control Surface Mutationcli/scaffold.js

HighPrevious Version Dangerous Deltascripts/pre-commit.sh

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

MediumEnvironment Vars

MediumShips Build Helperscripts/pre-commit.sh

MediumStructural Risk Force Deep Review

Low

Affected versions and remediation

This report applies to create-chemx@26.9.16-1408.

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

Avoid installing create-chemx@26.9.16-1408. Remove it from direct dependencies and check your lockfile for transitive copies.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.
If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.

Evidence last updated: 2026-10-12 08:10:53.385Z (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

Related packages

Other AI-agent control-surface risk packages

Behavioral surface

Related packages

Other AI-agent control-surface risk packages

Source & flagged code