registry / AI-agent control-surface risk / chemx / 26.9.24-393

chemx@26.9.24-393

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 mutates consumer AI-agent control surfaces by registering a runnable MCP server without consent. This meets the lifecycle control-hijack blocking criterion even though the integration aligns with the package's starter-kit purpose.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

Installing the package through npm triggers its postinstall script.

Impact

An AI agent using one of those configurations can invoke the package's MCP capabilities without the user separately choosing the integration.

Mechanism

The hook invokes the MCP installer, which writes server configuration for Cursor and VS Code and may also update Antigravity's global configuration to run the chemx MCP command.

Policy narrative

The package's npm postinstall hook calls the MCP installer for the consuming project. The installer writes a server entry to Cursor and VS Code project configuration and can also register the server in Antigravity's global configuration. No consent check guards these lifecycle changes, which expose the package's MCP tools to configured agents.

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 identified this as a dangerous AI-agent capability at 94.0% confidence with low false-positive risk.

Evidence for policy risk

package.json runs cli/postinstall.js automatically; that hook targets the consuming project and calls installAllMcpConfigs without a consent check.
The MCP installer writes a Chemical X server entry into the consumer's Cursor and VS Code configuration files and registers it in Antigravity's global MCP configuration when present.
The injected server runs this package's MCP command, making the lifecycle mutation an active agent capability rather than inert configuration.
The separate AGENTS.md installer adds directives steering agent file inspection and command choices; its installer is also available through the interactive wizard.

Evidence against

The package presents itself as a starter kit, and the MCP server setup is consistent with that product function.
The pillars wizard asks the user to select agent steering configuration, but that prompt does not guard the automatic postinstall MCP changes.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetwork

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

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/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

Lines 1-21javascript

1import fs from 'node:fs';

2import path from 'node:path';

3import os from 'node:os';

4import { syncAntigravityMcpSchemas } from './antigravity.js';

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 = 4925 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@26.9.24-393.

See all versions of chemx for other recorded verdicts.

Avoid installing chemx@26.9.24-393. 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 06:58:50.910Z (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