registry / AI-agent control-surface risk / chemx / 26.9.20-1318

chemx@26.9.20-1318

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

AI Security Review

scanned 11d ago · by lpm-firewall-ai

Source confirms an unconsented postinstall write to the consumer project's Cursor MCP configuration. This is a concrete foreign AI-agent control-surface mutation, so the package is malicious under the install-hook policy.

Static reason

High-risk behavior combination matched malicious policy.

Trigger

Installing the package through npm runs its postinstall hook.

Impact

The consumer's AI-agent environment gains a package-provided MCP server configuration.

Mechanism

The hook targets the consumer directory and calls the MCP installer, which creates or updates .cursor/mcp.json without a consent guard.

Policy narrative

During npm installation, the package's postinstall hook calls the MCP configuration installer against the consumer directory. That installer writes a Chemical X server entry to the project's Cursor MCP configuration without an interactive consent check, creating an AI-agent control surface as an install-time side effect.

AI rationale

Evidence

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

The package runs a postinstall script that invokes the MCP config installer for the consumer directory without a consent check.
The installer creates or updates the consumer's Cursor MCP configuration during that lifecycle run.
This automatically adds a package-owned agent control surface to consumer project configuration.

Evidence against

The installer merges MCP configuration instead of replacing the whole file.
The package's CLI also exposes setup functionality, consistent with its stated developer tooling purpose.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

scanned 212 file(s), 1.16 MB of source, external domains: api.github.com, cdn.jsdelivr.net, chemicalx.xophz.com, example.com, fallback.com, github.com, img.shields.io, mycompassconsulting.com, reports.chemicalx.xophz.com, unpkg.com, www.w3.org

Source & flagged code

10 flagged

package.jsonView file

Lines 27-67json

27 "README.md",

28 "LICENSE",

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 "typecheck": "tsc --noEmit",

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

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

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L47

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg · L47

48 "chemx:mcp": "chemx mcp",

49 "chemx:verify": "chemx verify",

50 "chemx:test": "chemx test",

51 "chemx:typecheck": "chemx typecheck"

52 },

53 "dependencies": {

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

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

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

57 "react": "^18.3.1",

58 "react-dom": "^18.3.1"

59 },

60 "devDependencies": {

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

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

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

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

65 "chemx": "26.9.20-408",

66 "typescript": "^5.9.3"

67 }

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 = 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 Medium4 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@26.9.20-1318.

See all versions of chemx for other recorded verdicts.

Avoid installing chemx@26.9.20-1318. 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 06:57:42.950Z (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