CVE-2026-33252 — HIGH (7.1)

Q: How severe is CVE-2026-33252?

CVE-2026-33252 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-33252?

Check the references section above for vendor advisories and patch information. Affected products include: Lfprojects Mcp Go Sdk.

Vulnerability 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 Score

7.1

HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

LOW

Affected Products

Vendor	Product	Versions
Lfprojects	Mcp Go Sdk	< 1.4.1

Related Weaknesses (CWE)

CWE-352

References

FAQ

What is CVE-2026-33252?

CVE-2026-33252 is a vulnerability with a CVSS score of 7.1 (HIGH). 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` he...

How severe is CVE-2026-33252?

CVE-2026-33252 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-33252?

Check the references section above for vendor advisories and patch information. Affected products include: Lfprojects Mcp Go Sdk.