CVE-2026-33252

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-33252
The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.1, the Go SDK's Streamable HTTP transport accepted browser-generated cross-site `POST` requests without validating the `Origin` header and without requiring `Content-Type: application/json`. In deployments without Authorization, especially stateless or sessionless configurations, this allows an arbitrary website to send MCP requests to a local server and potentially trigger tool execution. Version 1.4.1 contains a patch for the issue.

7.1 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 2.8 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact LOW

Scope UNCHANGED

References
Link Resource
https://github.com/modelcontextprotocol/go-sdk/commit/a433a831d6e5d5ac3b9e625a8095aa8eaa040dfc Patch
https://github.com/modelcontextprotocol/go-sdk/security/advisories/GHSA-89xv-2j6f-qhc8 Patch Vendor Advisory
Configurations

Configuration 1 (hide)

cpe:2.3:a:lfprojects:mcp_go_sdk:*:*:*:*:*:*:*:*
History

15 Apr 2026, 16:33

Type Values Removed Values Added
References () https://github.com/modelcontextprotocol/go-sdk/commit/a433a831d6e5d5ac3b9e625a8095aa8eaa040dfc - () https://github.com/modelcontextprotocol/go-sdk/commit/a433a831d6e5d5ac3b9e625a8095aa8eaa040dfc - Patch
References () https://github.com/modelcontextprotocol/go-sdk/security/advisories/GHSA-89xv-2j6f-qhc8 - () https://github.com/modelcontextprotocol/go-sdk/security/advisories/GHSA-89xv-2j6f-qhc8 - Patch, Vendor Advisory
First Time Lfprojects
Lfprojects mcp Go Sdk
CPE cpe:2.3:a:lfprojects:mcp_go_sdk:*:*:*:*:*:*:*:*
Summary
  • (es) El SDK de Go MCP utilizaba el encoding/json estándar de Go. Antes de la versión 1.4.1, el transporte HTTP Streamable del SDK de Go aceptaba solicitudes 'POST' de sitio cruzado generadas por el navegador sin validar el encabezado 'Origin' y sin requerir 'Content-Type: application/json'. En implementaciones sin autorización, especialmente configuraciones sin estado o sin sesión, esto permite a un sitio web arbitrario enviar solicitudes MCP a un servidor local y potencialmente activar la ejecución de herramientas. La versión 1.4.1 contiene un parche para el problema.

24 Mar 2026, 00:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-24 00:16

Updated : 2026-04-15 16:33

NVD link : CVE-2026-33252

Mitre link : CVE-2026-33252

CVE.ORG link : CVE-2026-33252

JSON object : View

Products Affected

lfprojects

  • mcp_go_sdk
CWE
CWE-352

Cross-Site Request Forgery (CSRF)