7.5High
CVE-2026-47427GitHub MCP Server: Nil Pointer Dereference DoS in completion/complete Handler
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.
Weakness (CWE):
CWE-476
Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.
Affected products and versions
| Vendor | Product | Versions | |
|---|---|---|---|
| github | github-mcp-server | < 1.1.0 | |
| github | mcp server | < 1.1.0 |
References and patches
- https://github.com/github/github-mcp-server/security/advisories/GHSA-w4q6-qw23-4rg7 ExploitVendor Advisory
- https://github.com/github/github-mcp-server/pull/2502 Issue TrackingPatch
- https://github.com/github/github-mcp-server/commit/c88d2ecdd3bb07f7bdd75296e3ee676febf14f58 Patch
- https://github.com/github/github-mcp-server/releases/tag/v1.1.0 Release Notes
CPE matches (NVD) (1)
cpe:2.3:a:github:mcp_server:*:*:*:*:*:*:*:*< 1.1.0