CVE-2026-34200
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 7.7 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.36% probability · 29th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-306, CWE-942
- Affected
- nhost/cli
- Source
- security-advisories@github.com
References
- https://github.com/nhost/nhost/commit/15eae9285f9dce63e184b9bb24616474ffa5ccc9Patch
- https://github.com/nhost/nhost/pull/4060Issue Tracking, Patch
- https://github.com/nhost/nhost/security/advisories/GHSA-6c5x-3h35-vvw2Exploit, Vendor Advisory
- https://github.com/nhost/nhost/security/advisories/GHSA-6c5x-3h35-vvw2Exploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.