CVE-2026-34200
HIGHNhost CLI MCP Server: Missing Inbound Authentication on Explicitly Bound Network Port
Title source: cnaExploitation Summary
EIP tracks 2 public exploits for CVE-2026-34200. PoCs published by skoveit, XZ1r0.
AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-34200, targeting the Nhost MCP Server. The vulnerability arises from a lack of authentication and permissive CORS policies, allowing unauthenticated cross-origin requests to execute administrative commands, leading to full infrastructure compromise.
Description
Nhost is an open source Firebase alternative with GraphQL. Prior to version 1.41.0, The Nhost CLI MCP server, when explicitly configured to listen on a network port, applies no inbound authentication and does not enforce strict CORS. This allows a malicious website visited on the same machine to issue cross-origin requests to the MCP server and invoke privileged tools using the developer's locally configured credentials. This vulnerability requires two explicit, non-default configuration steps to be exploitable. The default nhost mcp start configuration is not affected. This issue has been patched in version 1.41.0.
Exploits (2)
This repository contains a functional exploit for CVE-2026-34200, targeting the Nhost MCP Server. The vulnerability arises from a lack of authentication and permissive CORS policies, allowing unauthenticated cross-origin requests to execute administrative commands, leading to full infrastructure compromise.
This repository contains a functional exploit PoC for CVE-2026-34200, demonstrating a CORS bypass and authentication bypass in the Nhost CLI's MCP server. The exploit leverages a malicious website to exfiltrate sensitive data via cross-origin requests.
References (3)
Scores
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H