CVE-2026-33252 (GCVE-0-2026-33252)

Vulnerability from cvelistv5 – Published: 2026-03-23 23:44 – Updated: 2026-03-24 18:39
VLAI
Title
MCP Go SDK Allows Cross-Site Tool Execution for HTTP Servers without Authorizatrion
Summary
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.
Severity
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-24 18:39 UTC
CWE
  • CWE-352 - Cross-Site Request Forgery (CSRF)
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7895 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
modelcontextprotocol go-sdk Affected: < 1.4.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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