Is CVE-2026-33252 actively exploited?

CVE-2026-33252 has no public evidence of in-the-wild exploitation as of 2026-04-15.

What is the CVSS score for CVE-2026-33252?

CVE-2026-33252 has a CVSS score of 7.1 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L.

How do I patch CVE-2026-33252?

Patch guidance is available from lfprojects security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-33252.

Which products are affected by CVE-2026-33252?

1 product: lfprojects mcp go sdk.

Fix CVE-2026-33252 - HIGH lfprojects mcp go sdk

Description

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.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L
Attack Vector: network
Complexity: low
Privileges: none
User Action: required
Scope: unchanged
Confidentiality: none
Integrity: high
Availability: low
Weaknesses: CWE-352 · Cross-Site Request Forgery

Metadata

Primary Vendor: LFPROJECTS
Published: 3/24/2026
Last Modified: 4/15/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

lfprojects : mcp_go_sdk

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-33252. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-33252

View on NIST NVD

CVE-2026-33252 vulnerability