Medium Risk

sb_update_user

Update a user in Supabase Auth. Can change email, phone, password, metadata, or ban the user.

Handles credentials or secrets (password); High parameter count (10 properties)

Part of the Supabase MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

AI agents use sb_update_user to create or modify resources in Supabase. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.

Without a policy, an AI agent could call sb_update_user repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Supabase.

Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.

supabase.yaml
tools:
  sb_update_user:
    rules:
      - action: allow
        rate_limit:
          max: 30
          window: 60

See the full Supabase policy for all 63 tools.

Tool Name sb_update_user
Category Write
MCP Server Supabase MCP Server
Risk Level Medium

View all 63 tools →

Agents calling write-class tools like sb_update_user have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.

What does the sb_update_user tool do? +

Update a user in Supabase Auth. Can change email, phone, password, metadata, or ban the user.. It is categorised as a Write tool in the Supabase MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on sb_update_user? +

Add a rule in your Intercept YAML policy under the tools section for sb_update_user. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Supabase MCP server.

What risk level is sb_update_user? +

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

Can I rate-limit sb_update_user? +

Yes. Add a rate_limit block to the sb_update_user rule in your Intercept 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 sb_update_user completely? +

Set action: deny in the Intercept policy for sb_update_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.

What MCP server provides sb_update_user? +

sb_update_user is provided by the Supabase MCP server (@supabase-community/supabase-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Supabase

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
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