npm

Coding Agents Still Install an MCP Server Archived in 2025

Glow Security's MCPhantom research (2 Nov 2026) says coding agents name archived MCP reference servers from model memory, not from a lookup; in 98% of the deprecated installs it reviewed the user had not asked for that package by name. Verified hands-on: ten headless Claude Code runs (Haiku 5.5 and Sonnet 5.5) plus a Codex run, each asked to write the MCP config for a GitHub, Postgres, Slack, browser and Brave server. Both models named the archived @modelcontextprotocol/server-postgres for Postgres; Sonnet also returned archived server-github, server-slack and server-brave-search; Haiku returned GitHub's hosted remote and Brave's own @brave/brave-search-mcp-server; Sonnet returned @playwright/mcp for the browser; Codex pointed at github/github-mcp-server. All the reference servers are deprecated on npm and live in modelcontextprotocol/servers-archived (archived, last push 2025-05-28, README states NO SECURITY GUARANTEES). This morning the npm deprecation text on the GitHub, Postgres and Puppeteer packages was rewritten from the generic contact-npm-support boilerplate to Archived and unmaintained; no security guarantees when issue #4785 was closed at 04:21 UTC; npx prints it and installs anyway.