NULL pointer dereference in GitHub Github-Mcp-Server
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.
EPSS: 0.004 (37.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Github Github-mcp-server — versions < 1.1.0
- Github Mcp_server
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-47427?
- CVE-2026-47427 is a high-severity vulnerability in GitHub Github-Mcp-Server, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-07-28.
- How severe is CVE-2026-47427?
- High severity. CVSS v3 base score is 7.5 out of 10.