Is CVE-2026-47427 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-47427?

CVE-2026-47427 has a CVSS v3 severity of HIGH (7.5).

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CVE-2026-47427

Description

GitHub MCP Server is GitHub's official MCP Server. Prior to 1.1.0, the CompletionsHandler function in pkg/github/server.go accesses params.Ref without first checking whether it is nil, so a completion/complete request with a missing or empty ref field triggers a nil pointer dereference and a Go runtime panic; because the crash occurs before any authentication or token validation, any unauthenticated client able to send JSON-RPC messages can crash the server, resulting in a complete denial of service. This issue is fixed in version 1.1.0.