CVE-2026-47427
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 3.1
- 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.8% chance of exploitation in the next 30 days; higher than 55% of CVEs (scores of 2026-10-25)
- CWE
- CWE-476
- Published
- Modified
- Record from
- the NVD, synced
Affected
- github:mcp_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w4q6-qw23-4rg7 | Go | github.com/github/github-mcp-server | <1.1.0 | 1.1.0 |
| GO-2026-6118 | Go | github.com/github/github-mcp-server | <1.1.0 | 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