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.

CVSS Vector

References

• https://github.com/github/github-mcp-server/commit/c88d2ecdd3bb07f7bdd75296e3ee676febf14f58
• https://github.com/github/github-mcp-server/pull/2502
• https://github.com/github/github-mcp-server/releases/tag/v1.1.0
• https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7
• https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7