AI agents invoke query_bloodhound to trigger actions in BloodHound MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
The tool likely executes arbitrary Cypher queries against a BloodHound database containing sensitive Active Directory attack path data. While the description is empty (lowering confidence), the server context and tool name strongly suggest it runs queries that could expose full AD topology, attack paths, credentials targets, and privilege escalation routes.
From the tool's definition Tool name 'query_bloodhound' on a server that 'allows security professionals to analyze Active Directory attack paths using natural language instead of complex Cypher queries' — implies execution of arbitrary Cypher queries against a BloodHound/Neo4j database.
Documented attack patterns abuse exactly the kind of access query_bloodhound gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and BloodHound MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for query_bloodhound:
{
"version": "1",
"default": "deny",
"tools": {
"query_bloodhound": {
"limits": [
{
"counter": "query_bloodhound_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}query_bloodhound stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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query_bloodhound. It is categorised as a Execute tool in the BloodHound MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the BloodHound MCP server in PolicyLayer and add a rule for query_bloodhound: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches BloodHound MCP. Nothing to install.
query_bloodhound is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the query_bloodhound rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for query_bloodhound. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
query_bloodhound is provided by the BloodHound MCP server (mordavid/bloodhound-mcp-ai). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from BloodHound MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
75 BloodHound MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.