MCPHunt: Benchmarking Credential Leakage in Multi-Server MCP Agents
A new benchmark called MCPHunt has been developed by researchers to identify non-adversarial credential propagation across multi-server MCP (Model Context Protocol) trust boundaries. This framework tackles an information-flow control challenge, where benign read/write permissions can unintentionally leak credentials between servers due to structural effects rather than malicious intent. MCPHunt presents three key innovations: (1) canary-based taint tracking that simplifies propagation detection to straightforward string matching; (2) a controlled environment design that includes risky, benign, and hard-negative scenarios to ensure pipeline integrity and manage credential-format issues; and (3) CRS (Credential Risk Stratification), which differentiates between task-mandated and policy-violating propagation. This benchmark focuses on isolating verbatim credential leakage, laying the groundwork for assessing cross-boundary data propagation in multi-server systems. The study is accessible on arXiv, ID 2604.27819.
Key facts
- MCPHunt is the first controlled benchmark for non-adversarial credential propagation in multi-server MCP agents.
- The benchmark uses canary-based taint tracking for objective string matching.
- It includes risky, benign, and hard-negative conditions to validate pipeline soundness.
- CRS stratification separates task-mandated from policy-violating credential propagation.
- The work addresses information-flow control problems in tool composition.
- Credential leakage is described as a structural side effect of workflow topology.
- The paper is published on arXiv with ID 2604.27819.
- The framework focuses on verbatim credential propagation across trust boundaries.
Entities
Institutions
- arXiv