---
id: "CVE-2026-63399"
kind: "vulnerability"
aliases: ["CVE-2026-63399"]
title: "Coop: unauthenticated GraphQL call creates organizations on public instances"
severity: "medium"
cvss: 6.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["coop", "graphql", "package", "roost", "self-hosted"]
not_affected_if: ["auth-required", "private-network", "version-1.0.0-or-later"]
published_at: "2026-10-30T23:17:14+00:00"
first_seen_at: "2026-10-30T23:26:12+00:00"
updated_at: "2026-10-30T23:28:07+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63399", "first_seen_at": "2026-10-30T23:26:12+00:00"}]
---

# Coop: unauthenticated GraphQL call creates organizations on public instances

Coop, an open source review and moderation tool from ROOST, lets an unauthenticated user create arbitrary organizations through its GraphQL createOrg mutation on a publicly reachable instance. Without rate limiting, an attacker can flood the database and logs, which could exhaust the database.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the Coop version in use; versions before `1.0.0` are affected.
- Check whether the instance's GraphQL API is reachable from the internet rather than only from an authenticated private network.

## Fix

- Move Coop to `1.0.0` or later.

## Timeline

- 2026-10-30T23:26:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-63399

## From the sources

Coop is an open source review and moderation tool from ROOST. Prior to 1.0.0, the `GraphQL` `Mutation.createOrg` operation allows an unauthenticated actor to create arbitrary organizations on a publicly accessible instance. In addition to creating noise in the logs, the lack of rate limiting could potentially lead to database exhaustion. Running the service on an authenticated private network prevents outside actors from directly querying the `GraphQL` API. This issue is fixed in version 1.0.0.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_