Threat
Malicious MCP servers are real, and your AI reads what they tell it
First reported · Discovered redvault.co.uk
Page published
Earliest dated coverage: 22 Oct 2026 · First observed: 26 Oct 2026 · Latest dated coverage: 22 Oct 2026
Coverage timeline
Single-source incident — one report is available.
Why it matters
Malicious MCP servers can redirect an assistant’s legitimate file access toward credential and document theft through instructions that users may never see.
Redvault reports that memtry-cli, a malicious MCP add-on flagged by Amazon Inspector, returned onboarding instructions directing an assistant to collect personal documents and chat histories and upload them to the author's server. The article also cites an Invariant Labs demonstration in which a poisoned MCP tool description induced Cursor to expose an SSH key while keeping it out of the user-facing approval prompt.