Creates a new database user for an existing Atlas project. User will have atlasAdmin role.
AI agents use create_atlas_user to create or update resources in MongoDB Atlas MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MongoDB Atlas MCP Server environment.
This is a Write operation—it creates a new resource (database user) with side effects. While creation is technically reversible, granting atlasAdmin role to a new user is a privileged modification that could enable unauthorized database access and manipulation. The high severity reflects the administrative permissions granted and potential for lateral movement or data compromise if misused by an agent.
From the tool's definition Tool description states it "Creates a new database user" with "atlasAdmin role". The action is reversible (user can be deleted) but grants significant administrative permissions to access and manage databases.
Documented attack patterns abuse exactly the kind of access create_atlas_user gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MongoDB Atlas MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for create_atlas_user:
{
"version": "1",
"default": "deny",
"tools": {
"create_atlas_user": {
"limits": [
{
"counter": "create_atlas_user_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}create_atlas_user stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Creates a new database user for an existing Atlas project. User will have atlasAdmin role. It is categorised as a Write tool in the MongoDB Atlas MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MongoDB Atlas MCP Server MCP server in PolicyLayer and add a rule for create_atlas_user: 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 MongoDB Atlas MCP Server. Nothing to install.
create_atlas_user is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the create_atlas_user 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 create_atlas_user. 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.
create_atlas_user is provided by the MongoDB Atlas MCP Server MCP server (mongodb-developer/mcp-mongodb-atlas). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MongoDB Atlas MCP Server, 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.
6 MongoDB Atlas MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.