CVE-2026-47427 — GitHub MCP Server: Nil Pointer Dereference DoS in completion/complete Handler
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 …
Published: 2026-07-28 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7