VQV Signal

SECURITY SOURCE-BACKED TECHNICAL

Log-To-Leak: Prompt Injection Attack Targets Tool-Using LLM Agents via MCP

A new arXiv paper studies Log-To-Leak, a prompt-injection attack on LLM agents that use the Model Context Protocol (MCP) to access external tools. The authors say the natural-language metadata describing those tools creates an injection surface, and they examine this within an established tool-poisoning category. Log-To-Leak is described as an additive post-hoc logging attack that causes a separate, attacker-controlled call to run after the final legitimate call. The snippet says its payload targets the user query and MCP server data, but the excerpt is cut off before giving further details on results.

Source: arXiv · arxiv.org Published 2026-10-26T18:20:24+00:00 Detected 2026-10-28T01:33:51+00:00
View original source

A new arXiv paper studies Log-To-Leak, a prompt-injection attack on LLM agents that use the Model Context Protocol (MCP) to access external tools. The authors say the natural-language metadata describing those tools creates an injection surface, and they examine this within an established tool-poisoning category. Log-To-Leak is described as an additive post-hoc logging attack that causes a separate, attacker-controlled call to run after the final legitimate call. The snippet says its payload targets the user query and MCP server data, but the excerpt is cut off before giving further details on results.

AI-assisted summary based on the listed source.

LLM agents increasingly access external tools through the Model Context Protocol (MCP), but the natural-language metadata used to describe those tools creates a prompt-injection surface. Within this established tool-poisoning surface, we study Log-To-Leak, an additive post-hoc logging attack that induces a...

Developers and companies deploying AI agents that connect to external tools through MCP could face data exposure if this attack pattern works in practice. The paper points to tool metadata as a path for injected instructions, so teams building agent integrations may need to review how they describe and trust third-party tools. Readers should watch for the full paper's experimental results and any responses from MCP maintainers or security tooling vendors.

Security-conscious readers may want to review the source and watch for practical exposure or mitigation details.

Signal Strength 95% Technical label SOURCE-BACKED Public Interest 26 Category SECURITY Reader Depth TECHNICAL

Signal Strength reflects source quality, relevance, freshness and evidence. Public Interest helps organize discovery; it is not proof of truth.

Public Interest components
Recognizable Entity Score 0 Practical Impact Score 28 Novelty Interest Score 48 Consequence Score 30 Curiosity Score 16 Shareability Score 42

VQV surfaced this signal because it is recent, relevant to AI Security, connected to arXiv.