Mittwald Traces 56 Compromised Hosting Projects to Its MCP Server
German hosting provider Mittwald says an attacker exploited a flaw in its Model Context Protocol (MCP) server on 27 October. The server let customers use AI assistants to manage hosting through the mStudio control panel. Mittwald says it examined 56 compromised projects and had found no further compromised projects after repeated scans. Mittwald’s incident disclosure · Mittwald’s MCP documentation
The incident reached customer projects
Mittwald says the attacker registered customer accounts, probed the service and used one of those accounts to exploit the MCP flaw. It detected unusual activity on 4 November, blocked the first account it had identified and shut down the MCP server after tracing the intrusion to it. Mittwald says the speed of the attacker’s actions suggests possible use of AI tools. Its disclosure gives no independent confirmation of which tools were used. Mittwald’s timeline
Access is returning while investigations continue
On 7 November, Mittwald said mStudio sign-in and SSH access were available again. Websites it had blocked as a precaution remained blocked. The company said its separate customer centre and the sites managed through that centre were outside the incident’s scope. It introduced passkeys for mStudio sign-in and said it would contact customers directly where further action was needed. Mittwald’s restoration update
Teams notified of a compromised project should preserve deployment and access records, review changes since 27 October and rotate credentials that were accessible from the affected project. A passkey protects future sign-ins. Recovery also requires checking what the attacker could already reach.
