ATR-2026-00062criticalTool Poisoningexperimental
Hidden Capability in MCP Skill
Detects MCP skills that expose hidden or undocumented capabilities beyond their declared tool schema. A skill may advertise a simple interface but accept hidden parameters like "debug_mode", "admin_override", or "raw_exec" that unlock dangerous functionality. This is a common pattern in trojaned MCP packages.
Severity
critical
Category
Tool Poisoning
Scan Target
mcp
Author
ATR Community
Response Actions
block toolquarantine sessionalertsnapshotkill agent
References
OWASP Agentic
ASI02:2026 - Tool Misuse and ExploitationASI05:2026 - Unexpected Code Execution
OWASP LLM
LLM03:2025 - Supply Chain VulnerabilitiesLLM06:2025 - Excessive Agency
MITRE ATLAS
AML.T0010 - ML Supply Chain Compromise