Vulnerability Report

CVE-2026-33252

Title: Cross-Site Request Forgery in Go MCP SDK

Arbitrary File Access

Proof Of Concept

No public PoC currently indexed for CVE-2026-33252.

CWE Category CWE-352

Published Date Mar 24, 2026

Modified Date Apr 15, 2026

Exploit Status Not Found

Score 7.1 CVSS v3.1

Exploit Probability (EPSS)

0.18%

Vulnerability Summary

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.

Impacted Vendors

lfprojects 1

Reference Links

https://github.com/modelcontextprotocol/go-sdk/commit/a433a831d6e5d5ac3b9e625a8095aa8eaa040dfc https://github.com/modelcontextprotocol/go-sdk/security/advisories/GHSA-89xv-2j6f-qhc8

CVSS v3.1

Source Entity [email protected]

Severity HIGH

7.1

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

CVSS v3.1

Source Entity [email protected]

Severity MEDIUM

6.5

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

REQUIRED

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

UNCHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-33252 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

April 15, 2026 MODIFIED

Vulnerability data updated via NVD.

April 15, 2026 MODIFIED

Vulnerability data updated via NVD.

March 24, 2026 MODIFIED

Vulnerability data updated via NVD.

March 24, 2026 MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK

Complexity LOW

Privileges N/A

Interaction REQUIRED

CVSS Vector String


                                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

Affected Stack

No specific products linked.