update_user_permission · Bitbucket MCP: Risk & Policy

WHAT IT DOES

What update_user_permission does on Bitbucket

AI agents use update_user_permission to create or update resources in Bitbucket — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Bitbucket environment.

WHY IT NEEDS A POLICY

Why update_user_permission needs a policy

This tool modifies user permissions and user data, which is a reversible Write operation. However, it affects access control, which has significant blast radius if misused by an AI agent to grant inappropriate permissions to users or modify critical account settings. The high severity reflects that permission changes can affect system security and user access across repositories and pipelines.

From the tool's definition Tool name 'update_user_permission' and description 'Update or add a user' indicate modification of user access permissions and user records.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_user_permission Rate-limited

update_user_permission 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_user_permission": {
      "limits": [
        {
          "counter": "update_user_permission_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Bitbucket, so you can run agents against it safely.

FAQ

Questions about update_user_permission

What does the update_user_permission tool do? +

Update or add a user. It is categorised as a Write tool in the Bitbucket MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_user_permission? +

Register the Bitbucket MCP server in PolicyLayer and add a rule for update_user_permission: 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 Bitbucket. Nothing to install.

What risk level is update_user_permission? +

update_user_permission is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit update_user_permission? +

Yes. Add a rate_limit block to the update_user_permission 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.

How do I block update_user_permission completely? +

Set action: deny in the PolicyLayer policy for update_user_permission. 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.

What MCP server provides update_user_permission? +

update_user_permission is provided by the Bitbucket MCP server (javimaligno/mcp-server-bitbucket). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.