Analysis
MCP Rug Pull Attacks: When a Trusted Server Changes
First reported · Discovered eseospace.com
Page published
Earliest dated coverage: 28 Oct 2026 · First observed: 11 Nov 2026 · Latest dated coverage: 28 Oct 2026
Coverage timeline
Single-source analysis — one report is available.
Why it matters
MCP rug pulls undermine one-time trust decisions, making ongoing tool-change monitoring and reapproval important safeguards against agent manipulation and data leakage.
MCP rug-pull attacks occur when a previously approved server changes its tool descriptions or behavior, introducing malicious instructions after the initial review. This reference explainer summarizes Invariant Labs' sleeper-server demonstration involving WhatsApp and recommends version pinning, tool-description hashing, and human approval of changes.