registry / chemx / 26.9.21-227

chemx@26.9.21-227

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

AI Security Review

scanned 11d ago · by lpm-firewall-ai

The automatic postinstall mutation of agent configuration is a real lifecycle risk, but the observed behavior installs this package’s own MCP integration. The broader steering-file writes are reachable through explicit installer choices, so the source does not establish a block-worthy control hijack.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

Installing the package with npm in a consumer project.

Impact

The IDE can start this package’s MCP server. No credential transfer or unrelated permission grant was identified in the inspected installation path.

Mechanism

The postinstall hook calls the MCP installer, which merges a chemx server entry into IDE configuration files and may add chemx helper scripts to the project package manifest.

AI rationale

Evidence

package.jsoncli/postinstall.jscli/mcp/installer.js.cursor/mcp.json.vscode/mcp.json~/.gemini/config/mcp_config.json

Decision evidence

public snapshot

AI called this Suspicious at 91.0% confidence as Dangerous Capability with medium false-positive risk.

Evidence for warning

The package runs a postinstall hook that calls the MCP configuration installer for the consumer directory.
The installer adds the package’s own MCP server to project Cursor and VS Code configuration files.
When an Antigravity config directory already exists, the installer also registers the package’s MCP server in the user-level config.
The broader AGENTS.md and editor-rules writes are performed through explicit installer and wizard flows.

Evidence against

The automatic setup is limited to registering this package’s own MCP server and related project scripts; inspected code does not show it granting unrelated install-script permissions or sending credentials.
The wider agent-steering file writes are reached through an interactive installer choice or wizard, not the postinstall hook.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStrings

Source & flagged code

10 flagged

package.jsonView file

Lines 29-69json

29 "docs",

30 "assets"

31 ],

32 "exports": {

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

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

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

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

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

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

39 "./patcher": "./cli/patcher.js",

40 "./errors": "./cli/errors/index.js"

41 },

42 "scripts": {

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

44 "test": "node --test cli/audit/*.spec.js cli/mcp/*.spec.js cli/build/*.spec.js cli/team/*.spec.js cli/errors/*.spec.js cli/*.spec.js",

45 "check:frameworks": "node scripts/check-framework-generation.mjs",

46 "prepublishOnly": "node scripts/check-framework-generation.mjs",

47 "typecheck": "tsc --noEmit",

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

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

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L49

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg · L49

50 "chemx:mcp": "chemx mcp",

51 "chemx:verify": "chemx verify",

52 "chemx:test": "chemx test",

53 "chemx:typecheck": "chemx typecheck"

54 },

55 "dependencies": {

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

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

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

59 "react": "^18.3.1",

60 "react-dom": "^18.3.1"

61 },

62 "devDependencies": {

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

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

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

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

67 "chemx": "26.9.20-408",

68 "typescript": "^5.9.3"

69 }

cli/errors/errors.spec.jsView file

Lines 7-47javascript

7 maskSensitiveTokens,

8 normalizeHomePath,

9 sanitizeText,

10 sanitizeStackTrace

11} from './sanitizer.js';

12import {

13 buildIssueTitle,

14 buildIssueBody,

15 buildIssueWebUrl,

16 formatIssueContent

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

cli/build/executor.jsView file

Lines 1-31javascript

1import { spawn } from 'node:child_process';

3export const executeBuild = (command, cwd = process.cwd(), options = {})

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

1Install-time code directly mutates a foreign AI-agent control surface: L20: export const mergeMcpServerConfig = (existingJsonString = '', serverDef = {}) => { L21: let parsed = { mcpServers: {} }; L22: ... L30: L31: const hasMcpServersObject = Boolean(parsed.mcpServers && typeof parsed.mcpServers === 'object'); L32: if (!hasMcpServersObject) { L33: parsed.mcpServers = {}; L34: } L35: L36: parsed.mcpServers[SERVER_KEY] = serverDef; L37: return JSON.stringify(parsed, null, 2) + '\n'; ... L90: const cursorDir = path.join(resolvedTarget, '.cursor'); Write operation from cli/mcp/installer.js: L20: export const mergeMcpServerConfig = (existingJsonString = '', serverDef = {}) => { L21: let parsed = { mcpServers: {} }; L22: ... L30: L31: const hasMcpServersObject = Boolean(parsed.mcpServers &

Critical

Ai Agent Control Hijack

Source creates an unconsented AI-agent control surface through install-time mutation or a default unauthenticated remote skill channel.

cli/mcp/installer.jsView on unpkg · L1

cli/pillars-wizard.jsView file

•Manifest-trigger-reachable source links an external AI-agent control path to a behavior-bearing write operation. st pick = usegum ? gumchoose(choices, 'select architectural pillars configuration') : await promptquestion('select pillars: [1=recommended, 2=strict, 3=custom, 4=minimal, 5=none] (default: 1): '); if (pick && (pick.startswith('2.') || pick === '2')) { selectedpresetkey = 'strict'; selectedpillarids = [...pillar_presets.strict.pillars]; } else if (pick && (pick.startswith('3.') || pick === '3')) { selectedpresetkey = 'custom'; for (const pillar of pillars) { const defaultchoice = pillar_presets.recommended.pillars.includes(pillar.id) ? 'y/n' : 'y/n'; const isdefaultyes = defaultchoice === 'y/n'; const answer = a

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/pillars-wizard.jsView on unpkg

scripts/pre-commit.shView file

•path = scripts/pre-commit.sh kind = build_helper sizeBytes = 5174 magicHex = [redacted]

Medium

Ships Build Helper

Package ships non-JavaScript build or shell helper files.

scripts/pre-commit.shView on unpkg

Source & flagged code

10 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/errors/errors.spec.jsView file

27patternName = github_pat severity = critical line = 27

Critical

Critical Secret

Package contains a critical-looking secret pattern.

cli/errors/errors.spec.jsView on unpkg · L27

Findings

3 Critical5 High5 Medium5 Low

CriticalCritical Secretcli/errors/errors.spec.js

CriticalAi Agent Control Hijackcli/mcp/installer.js

CriticalSecret Patterncli/errors/errors.spec.js

HighInstall Time Lifecycle Scriptspackage.json

HighChild Processcli/audit-preflight-git.js

HighShellcli/build/executor.js

HighSame File Env Network Executioncli/license.js

HighTrigger Reachable External Ai Agent Control Surface Mutationcli/pillars-wizard.js

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

MediumEnvironment Vars

MediumShips Build Helperscripts/pre-commit.sh

Affected versions and remediation

This report applies to chemx@26.9.21-227.

See all versions of chemx for other recorded verdicts.

Review the evidence and your use of chemx@26.9.21-227 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: 2026-10-12 06:57:53.815Z (UTC).

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