Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M
CVE-2026-34200Nhost CLI MCP Server: Missing Inbound Authentication on Explicitly Bound Network Port
High 7.7
In plain English
A high-severity missing authentication in nhost from nhost. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official 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.
Affected products (as reported)
Weakness: CWE-306, CWE-942 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/nhost/nhost/security/advisories/GHSA-6c5x-3h35-vvw2 x_refsource_CONFIRM
- https://github.com/nhost/nhost/pull/4060 x_refsource_MISC
- https://github.com/nhost/nhost/commit/15eae9285f9dce63e184b9bb24616474ffa5ccc9 x_refsource_MISC