Study finds AI coding agents keep installing long-deprecated MCP servers

On November 2, 2026, Glow Security published research it calls MCPhantom, reporting that AI coding agents continue to install MCP servers that were archived more than a year ago. According to the study, in 98% of the sessions where an agent set up one of these deprecated servers, the user had never requested it by name. Instead, the agent filled in the package name from what its model remembered. Help Net Security picked up the story on November 3. On November 4, an author on DEV Community decided to check whether the practice was still happening at scale. Using the npm public download API, they looked at the 12 deprecated @modelcontextprotocol packages named in the research and found that, over the week from October 27 to November 2, they had been downloaded roughly 620,000 times in total. The author also noted that npx -y merely prints a warning and proceeds with the install, so the deprecation flag does not stop usage. As of the available reporting, the picture stops there: one vendor study and one independent data check line up on the same point, and no explanation has been published by the parties responsible for the packages.