Bug 2450542 (CVE-2026-33252) - CVE-2026-33252 encoding/json: golang: github.com/modelcontextprotocol/go-sdk: Go MCP SDK: Remote tool execution via cross-site request forgery
Summary: CVE-2026-33252 encoding/json: golang: github.com/modelcontextprotocol/go-sdk:...
Keywords:
Status: NEW
Alias: CVE-2026-33252
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2450665 2450666 2450667 2450668
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-03-24 00:01 UTC by OSIDB Bzimport
Modified: 2026-03-24 09:39 UTC (History)
24 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)

Description OSIDB Bzimport 2026-03-24 00:01:52 UTC 
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.
Note You need to log in before you can comment on or make changes to this bug.