REDHAT-BUG-2442903: High severity go Go MCP SDK vulnerability
The Go MCP SDK used Go's standard encoding/json.Unmarshal for JSON-RPC and MCP protocol message parsing in versions prior to 1.3.1. Go's standard library performs case-insensitive matching of JSON keys to struct field tags — a field tagged json:"method" would also match "Method", "METHOD", etc. This violated the JSON-RPC 2.0 specification, which defines exact field names. A malicious MCP peer may have been able to send protocol messages with non-standard field casing that the SDK would silently accept. This had the potential for bypassing intermediary inspection and coss-implementation inconsistency. Go's standard JSON unmarshaling was replaced with a case-sensitive decoder in commit 7b8d81c. Users are advised to update to v1.3.1 to resolve this issue.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Go MCP SDKto a version that resolves this vulnerability.Fixed in 1.3.1Patch 7b8d81c
Event History
Frequently Asked Questions
What is the severity of REDHAT-BUG-2442903?
The severity of REDHAT-BUG-2442903 is high, rated at 7.
How do I fix REDHAT-BUG-2442903?
To address REDHAT-BUG-2442903, update the Go MCP SDK to version 1.3.1 or later.
What versions are affected by REDHAT-BUG-2442903?
Versions of the Go MCP SDK prior to 1.3.1 are affected by REDHAT-BUG-2442903.
What is the main issue caused by REDHAT-BUG-2442903?
REDHAT-BUG-2442903 involves case-insensitive matching of JSON keys that can lead to protocol message parsing vulnerabilities.
Is there a workaround for REDHAT-BUG-2442903?
There are no official workarounds for REDHAT-BUG-2442903; updating the SDK is the recommended solution.