CVE-2026-47427
HIGH
NVD
CVSS Score
7.5
Severity
HIGH
Published
Jul 28, 2026
Vendor
unknown
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.
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