---
id: 1410
title: "Jumping the line: How MCP servers can attack you before you ever use them"
source_domain: blog.trailofbits.com
source_url: "https://blog.trailofbits.com/2025/04/21/jumping-the-line-how-mcp-servers-can-attack-you-before-you-ever-use-them/"
published_at: "2025-04-21 14:30"
tags: ["ai-security", "mcp", "prompt-injection", "llm-security", "ai-agents", "tool-poisoning", "trail-of-bits"]
phying_url: "https://phying.com/item/1410"
lang: en
---

# Jumping the line: How MCP servers can attack you before you ever use them

## Summary

MCP's 'line jumping' vulnerability lets malicious servers inject prompts through tool descriptions to manipulate AI behavior before tools are ever invoked.

## Intelligence Metadata

- **Sources:** blog.trailofbits.com
- **Published:** 2025-04-21 14:30
- **Original:** https://blog.trailofbits.com/2025/04/21/jumping-the-line-how-mcp-servers-can-attack-you-before-you-ever-use-them/
- **Phying News:** https://phying.com/item/1410